diff --git a/Makefile b/Makefile
index 8b938b78..93c4b36e 100644
--- a/Makefile
+++ b/Makefile
@@ -411,6 +411,7 @@ TESTS	= $(BIN)/test_smoke $(BIN)/test_lex $(BIN)/test_parse $(BIN)/test_check \
 	  $(BIN)/test_star_fn_deref \
 	  $(BIN)/test_star_fn_deref_call \
 	  $(BIN)/test_match_variant_dispatch \
+	  $(BIN)/test_strict_package \
 	  $(BIN)/test_io_types_run \
 	  $(BIN)/test_dot_aliased_ptr \
 	  $(BIN)/test_return_tagged_forward \
@@ -649,6 +650,13 @@ $(BIN)/test_unknowndecl_reject: test/wcc/989_unknowndecl_reject.c \
 		$(LIB)/libwwrt.a | $(BIN)
 	$(CC) $(CFLAGS) -o $@ $<
 
+# 782_strict_package (#24a): every primary section must open with a `package`
+# clause; a missing clause on the first decl is a hard error, symmetric on
+# cstage w6c + wwstage w6c_ww. Each reject row reddens under a gate revert.
+$(BIN)/test_strict_package: test/wcc/782_strict_package.c \
+		$(BIN)/w6c $(BIN)/w6c_ww | $(BIN)
+	$(CC) $(CFLAGS) -o $@ $<
+
 # 989_nullableglobal_reject (#45 silent->loud bridge, task #15 prereq): a
 # module-level nullable `(*T | void)` GLOBAL has no storage path, so a
 # match/is/as on it silently miscompiled (0(BP) read / undefined ref) on
diff --git a/cmd/wcc/parse.c b/cmd/wcc/parse.c
index 9afa7fc0..8c17b3ee 100644
--- a/cmd/wcc/parse.c
+++ b/cmd/wcc/parse.c
@@ -1407,18 +1407,16 @@ parsefile(Parser *p)
 	Pos pp = { p->l->file, 1, 1 };
 	Node *file = newnode(p->a, N_FILE, pp);
 	Node *head = NULL, *tail = NULL;
+	int sawpackage = 0;
 	while (p->cur.kind != TK_EOF) {
-		/* `package foo;` — directory-as-module declaration. Each
-		 * .ww file's section in a concatenated stream begins with
-		 * one; a single-file or fragment input may omit it (curmod
-		 * stays NULL and decls are treated as primary).
-		 *
-		 * Retained divergence from brief: the strict missing-`package`
-		 * error was softened to silent-default to keep 63 inline-source
-		 * test wrappers (200_parse, 100_lex, 300_check, ...) parsing.
-		 * See task #23 for the wrapper migration that unblocks the
-		 * strict check. Rule 7 + rule 8 documentation. */
+		/* `package foo;` — directory-as-module declaration. Every
+		 * primary section opens with one (`package main;` for an
+		 * executable); a missing clause on the first real decl is a
+		 * hard error (strict-package, #24a). Imported (pathmod) and
+		 * sep primary-reset (resetmod) regions carry identity
+		 * out-of-band and are exempt. */
 		if (p->cur.kind == TK_MODULE) {
+			sawpackage = 1;
 			advance(p);
 			const char *name = expectident(p);
 			expect(p, TK_SEMI);
@@ -1457,6 +1455,7 @@ parsefile(Parser *p)
 		 * leaf `package` clause, and are flagged imported (gates the
 		 * root-only bare-`main` rule, #32). */
 		if (p->cur.kind == TK_MODPATH) {
+			sawpackage = 0;
 			p->pathmod = p->cur.text;
 			p->curmod = p->cur.text;
 			p->resetmod = NULL;
@@ -1472,6 +1471,7 @@ parsefile(Parser *p)
 		 * directive after a mid-file `package` would strip subsequent
 		 * decls to bare — that usage is deliberate-only. */
 		if (p->cur.kind == TK_MODRESET) {
+			sawpackage = 0;
 			/* #57: a path-carrying reset (sep primary body) mangles
 			 * decls on the dotted path so definer == importer, but
 			 * leaves imported==0 (curmod set, pathmod NULL) so -c
@@ -1498,6 +1498,16 @@ parsefile(Parser *p)
 			}
 			continue;
 		}
+		/* strict-package: a primary section's first real decl must be
+		 * preceded by a `package` clause. Imported (pathmod) and sep
+		 * primary-reset (resetmod) regions carry identity out-of-band,
+		 * so they are exempt. Wording mirrors Go's missing-`package`
+		 * diagnostic (rule 5; Hare has no clause to port). */
+		if (p->pathmod == NULL && p->resetmod == NULL && !sawpackage) {
+			errorf(p->cur.pos, "missing package clause");
+			p->errs++;
+			sawpackage = 1;
+		}
 		Node *attrs = parseattrs(p);
 		int exp = accept(p, TK_EXPORT);
 		Node *d = NULL;
diff --git a/lib/ww/syntax/parse.ww b/lib/ww/syntax/parse.ww
index b8b8ad48..5e6a3025 100644
--- a/lib/ww/syntax/parse.ww
+++ b/lib/ww/syntax/parse.ww
@@ -416,17 +416,16 @@ export fn parsefile(p: *parser) *node = {
 	let f = newnode(nkind.N_FILE, p.curfile, p.curline, p.curcol);
 	let head: *node = nil;
 	let tail: *node = nil;
+	let sawpackage: i32 = 0;
 	for (p.curkind != tkind.TK_EOF) {
-		// `package foo;` — each contributing source's section in a
-		// concatenated stream begins with one. Single-file inputs
-		// may omit it (curmod stays empty; decls treated as primary).
-		//
-		// Retained divergence from brief: strict missing-`package`
-		// error softened to silent-default — 63 inline-source test
-		// wrappers depend on the soft behavior. See task #23 for
-		// the wrapper migration that unblocks the strict check.
-		// Rule 7 + rule 8 documentation.
+		// `package foo;` — directory-as-module declaration. Every
+		// primary section opens with one (`package main;` for an
+		// executable); a missing clause on the first real decl is a
+		// hard error (strict-package, #24a). Imported (pathmod) and
+		// sep primary-reset (resetmod) regions carry identity
+		// out-of-band and are exempt.
 		if (p.curkind == tkind.TK_MODULE) {
+			sawpackage = 1;
 			advance(p);
 			let name: str;
 			expectident(p, &name);
@@ -462,6 +461,7 @@ export fn parsefile(p: *parser) *node = {
 		// leaf `package` clause, and are flagged imported (gates the
 		// root-only bare-`main` rule, #32).
 		if (p.curkind == tkind.TK_MODPATH) {
+			sawpackage = 0;
 			p.pathmod = p.curtext;
 			p.curmod = p.curtext;
 			p.resetmod = "";
@@ -477,6 +477,7 @@ export fn parsefile(p: *parser) *node = {
 		// directive after a mid-file `package` would strip subsequent
 		// decls to bare — that usage is deliberate-only.
 		if (p.curkind == tkind.TK_MODRESET) {
+			sawpackage = 0;
 			// #57: a path-carrying reset (sep primary body) mangles decls
 			// on the dotted path so definer == importer, but leaves
 			// imported==0 (curmod set, pathmod "") so -c primary-ness and
@@ -503,6 +504,15 @@ export fn parsefile(p: *parser) *node = {
 			};
 			continue;
 		};
+		// strict-package: a primary section's first real decl must be
+		// preceded by a `package` clause. Imported (pathmod) and sep
+		// primary-reset (resetmod) regions carry identity out-of-band,
+		// so they are exempt. Wording mirrors Go's missing-`package`
+		// diagnostic (rule 5; Hare has no clause to port).
+		if (p.pathmod.len == 0 && p.resetmod.len == 0 && sawpackage == 0) {
+			errmsg(p, "missing package clause");
+			sawpackage = 1;
+		};
 		let attrs = parseattrs(p);
 		let exported: i32 = 0;
 		if (p.curkind == tkind.TK_EXPORT) { exported = 1; advance(p); };
diff --git a/rt/ensure.ww b/rt/ensure.ww
index f8fa8def..0a5fba30 100644
--- a/rt/ensure.ww
+++ b/rt/ensure.ww
@@ -14,10 +14,13 @@
 // no per-type wrapper functions (appendu8 / appendi64) needed.
 //
 // User code never `use`s this — the symbol is resolved at link time
-// from libwwrt.a, like rt_malloc and rt_streq. No `module` declaration:
-// rt/ensure.ww is compiled standalone via `w6c rt/ensure.ww` (not
-// through the driver), and its `export fn rt_ensure` must keep its
-// bare symbol name so the linker resolves it.
+// from libwwrt.a, like rt_malloc and rt_streq. rt/ensure.ww is compiled
+// standalone via `w6c rt/ensure.ww` (not through the driver). Under
+// strict-package (#24a) it declares `package rt;` (matching its
+// directory) like every primary section; the link-resolved name is
+// pinned bare via @symbol on the export (the clause would otherwise
+// mangle it to rt.rt_ensure).
+package rt;
 
 @symbol("rt_malloc") fn malloc(n: u64) *void;
 
@@ -31,7 +34,7 @@ type slice = struct {
 	cap: i64,
 };
 
-export fn rt_ensure(s: *slice, membsz: u64) void = {
+@symbol("rt_ensure") export fn rt_ensure(s: *slice, membsz: u64) void = {
 	if (s.cap >= s.len) { return; };
 	let nc: i64 = s.cap * 2i64;
 	if (nc < 8i64) { nc = 8i64; };
diff --git a/rt/malloc.ww b/rt/malloc.ww
index 770b525a..d7bb8b2a 100644
--- a/rt/malloc.ww
+++ b/rt/malloc.ww
@@ -1,6 +1,8 @@
 // rt/malloc.ww — bump allocator over 2MiB chunks. Archived into
-// libwwrt.a, compiled standalone (no `module`) with bare symbols, like
-// rt/ensure.ww.
+// libwwrt.a, compiled standalone with bare symbols, like rt/ensure.ww.
+// Under strict-package (#24a) it declares `package rt;` (matching its
+// directory); the export's link name stays bare via its own
+// @symbol("rt_malloc").
 //
 // WHY bump, replacing the page-per-call mmap (rt_segmalloc, ex-rt_malloc):
 // the old rt_malloc page-rounded every request, so a 32-72B node cost a
@@ -15,6 +17,7 @@
 // Zero-init is preserved: every byte handed out is fresh from
 // MAP_ANONYMOUS (kernel-zeroed) and never reused, so alloc(T{})'s
 // zero-fill still holds. Lazy first chunk falls out of cur=rem=0.
+package rt;
 
 def CHUNKSZ: u64 = 2097152u64;	// 1<<21, ref/hare/rt/malloc.ha:24
 def ALIGN:   u64 = 16u64;	// ref/hare/rt/malloc.ha:14
diff --git a/test/wcc/200_parse.c b/test/wcc/200_parse.c
index 9ca9e591..67132990 100644
--- a/test/wcc/200_parse.c
+++ b/test/wcc/200_parse.c
@@ -11,6 +11,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
+#include "wwtestpkg.h"
 
 static int
 must_parse(const char *src)
@@ -18,10 +19,12 @@ must_parse(const char *src)
 	Arena *a = newarena();
 	Lex l;
 	Parser p;
-	lexinit(&l, a, "<test>", src, strlen(src));
+	char *ws = wwtest_wrap(src);
+	lexinit(&l, a, "<test>", ws, strlen(ws));
 	parserinit(&p, a, &l);
 	Node *n = parsefile(&p);
 	int ok = (n != NULL && p.errs == 0 && l.errs == 0);
+	free(ws);
 	freearena(a);
 	return ok;
 }
@@ -32,7 +35,8 @@ parse_to_str(const char *src, int *errs)
 	Arena *a = newarena();
 	Lex l;
 	Parser p;
-	lexinit(&l, a, "<test>", src, strlen(src));
+	char *ws = wwtest_wrap(src);
+	lexinit(&l, a, "<test>", ws, strlen(ws));
 	parserinit(&p, a, &l);
 	Node *n = parsefile(&p);
 	*errs = p.errs + l.errs;
@@ -41,6 +45,7 @@ parse_to_str(const char *src, int *errs)
 	size_t len = 0;
 	FILE *f = open_memstream(&buf, &len);
 	if (f == NULL) {
+		free(ws);
 		freearena(a);
 		return NULL;
 	}
@@ -51,6 +56,7 @@ parse_to_str(const char *src, int *errs)
 	memcpy(out, buf, len);
 	out[len] = '\0';
 	free(buf);
+	free(ws);
 	freearena(a);
 	return out;
 }
diff --git a/test/wcc/300_check.c b/test/wcc/300_check.c
index 2f4fe981..88e2a1d3 100644
--- a/test/wcc/300_check.c
+++ b/test/wcc/300_check.c
@@ -8,6 +8,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
+#include "wwtestpkg.h"
 
 static int
 runrow(const char *src, const char *expect)
@@ -16,7 +17,8 @@ runrow(const char *src, const char *expect)
 	Lex l;
 	Parser p;
 	Checker c;
-	lexinit(&l, a, "<test>", src, strlen(src));
+	char *ws = wwtest_wrap(src);
+	lexinit(&l, a, "<test>", ws, strlen(ws));
 	parserinit(&p, a, &l);
 	Node *file = parsefile(&p);
 
@@ -44,6 +46,7 @@ runrow(const char *src, const char *expect)
 			    "  src: %s\n", expect, errbuf, src);
 	}
 	free(errbuf);
+	free(ws);
 	freearena(a);
 	return ok;
 }
diff --git a/test/wcc/400_w6c.c b/test/wcc/400_w6c.c
index bbe50cf7..b4921a04 100644
--- a/test/wcc/400_w6c.c
+++ b/test/wcc/400_w6c.c
@@ -8,6 +8,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
+#include "wwtestpkg.h"
 
 static int
 run6c(const char *src, char **out)
@@ -16,7 +17,7 @@ run6c(const char *src, char **out)
 	snprintf(path, sizeof path, "/tmp/wwt_%d.ww", getpid());
 	FILE *f = fopen(path, "wb");
 	if (f == NULL) return -1;
-	fputs(src, f);
+	wwtest_fputs(src, f);
 	fclose(f);
 
 	char cmd[256];
@@ -60,7 +61,7 @@ static const struct row rows[] = {
 	{ "fn cond(x: i32) i32 = { if (x > 0) { return 1; }; return 0; };",
 	  "CMPQ\t$0, AX" },
 	{ "fn lo() void = { for (let i: i32 = 0; i < 10; i += 1) { }; };", "JMP" },
-	{ "fn callit() i32 = { return 1; };", "TEXT callit,$0" },
+	{ "fn callit() i32 = { return 1; };", "TEXT main.callit,$0" },
 };
 
 int
diff --git a/test/wcc/500_w6a.c b/test/wcc/500_w6a.c
index 72958819..abb28b55 100644
--- a/test/wcc/500_w6a.c
+++ b/test/wcc/500_w6a.c
@@ -7,6 +7,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
+#include "wwtestpkg.h"
 
 static int
 run(const char *cmd)
@@ -35,7 +36,7 @@ main(void)
 	int n = 0, fail = 0;
 	for (int i = 0; programs[i]; i++, n++) {
 		FILE *f = fopen(src, "wb");
-		fputs(programs[i], f);
+		wwtest_fputs(programs[i], f);
 		fclose(f);
 
 		char cmd[512];
diff --git a/test/wcc/600_w6l.c b/test/wcc/600_w6l.c
index edd8a278..743b2487 100644
--- a/test/wcc/600_w6l.c
+++ b/test/wcc/600_w6l.c
@@ -6,6 +6,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
+#include "wwtestpkg.h"
 
 int
 main(void)
@@ -20,7 +21,7 @@ main(void)
 	snprintf(exe, sizeof exe, "/tmp/wwt_%d.x", getpid());
 
 	FILE *f = fopen(src, "wb");
-	fputs("fn main() i32 = { return 42; };", f);
+	wwtest_fputs("fn main() i32 = { return 42; };", f);
 	fclose(f);
 
 	char cmd[1024];
diff --git a/test/wcc/610_arch.c b/test/wcc/610_arch.c
index 3336fe99..336f5d33 100644
--- a/test/wcc/610_arch.c
+++ b/test/wcc/610_arch.c
@@ -13,6 +13,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int run(const char *cmd) { return system(cmd); }
 
@@ -33,24 +34,26 @@ main(void)
 	snprintf(dir, sizeof dir, "/tmp/wwarch_%d", getpid());
 	mkdir(dir, 0755);
 
-	/* lib_good.ww — defines f1() */
+	/* lib_good.ww — defines f1() (→ main.f1 under strict-package #24a) */
 	char path[256];
 	snprintf(path, sizeof path, "%s/lib_good.ww", dir);
 	FILE *f = fopen(path, "wb");
-	fputs("export fn f1() i32 = { return 7; };", f);
+	wwtest_fputs("export fn f1() i32 = { return 7; };", f);
 	fclose(f);
 
 	/* lib_bad.ww — defines f2() but also references an undefined extern */
 	snprintf(path, sizeof path, "%s/lib_bad.ww", dir);
 	f = fopen(path, "wb");
-	fputs("@symbol(\"this_symbol_does_not_exist\") fn bogus() i32;\n"
+	wwtest_fputs("@symbol(\"this_symbol_does_not_exist\") fn bogus() i32;\n"
 	      "export fn f2() i32 = { return bogus(); };", f);
 	fclose(f);
 
-	/* main.ww — calls f1, NOT f2 */
+	/* main.ww — calls f1, NOT f2. The plain prototype declares f1 in the
+	 * same (main) module, so the call resolves to main.f1 — matching
+	 * lib_good's moduled definition (no @symbol bare-pin needed). */
 	snprintf(path, sizeof path, "%s/m.ww", dir);
 	f = fopen(path, "wb");
-	fputs("@symbol(\"f1\") fn f1() i32;\n"
+	wwtest_fputs("fn f1() i32;\n"
 	      "fn main() i32 = { return f1(); };", f);
 	fclose(f);
 
diff --git a/test/wcc/630_let_global.c b/test/wcc/630_let_global.c
index 7ef8abf6..407ce091 100644
--- a/test/wcc/630_let_global.c
+++ b/test/wcc/630_let_global.c
@@ -12,6 +12,7 @@
 #include <stdlib.h>
 #include <unistd.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 run_exit(const char *cmd)
@@ -33,7 +34,7 @@ build_and_run(const char *bin, const char *prog)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) return -1;
-	fputs(prog, f);
+	wwtest_fputs(prog, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s/ww run %s", bin, src);
diff --git a/test/wcc/631_def_neg_global.c b/test/wcc/631_def_neg_global.c
index 59f2e36c..c2268b73 100644
--- a/test/wcc/631_def_neg_global.c
+++ b/test/wcc/631_def_neg_global.c
@@ -42,6 +42,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -142,7 +143,7 @@ run_driver(const char *driver, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) { runwait(rmcmd); return -1; }
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s build -o %s %s 2>/dev/null",
@@ -174,7 +175,7 @@ asm_byte_identical(const char *bin, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) return -1;
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s/w6c -o %s %s 2>/dev/null", bin, cs, src);
diff --git a/test/wcc/632_w6l_manyflags.c b/test/wcc/632_w6l_manyflags.c
index 94c18515..fb4438f6 100644
--- a/test/wcc/632_w6l_manyflags.c
+++ b/test/wcc/632_w6l_manyflags.c
@@ -18,6 +18,7 @@
 #include <string.h>
 #include <unistd.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static const char *
 absbin(void)
@@ -98,10 +99,10 @@ main(void)
 
 	/* a standalone main.o (no undefs) + an unrelated archived foo.o. */
 	FILE *f = fopen(src, "wb");
-	fputs("fn main() i32 = { return 42; };", f);
+	wwtest_fputs("fn main() i32 = { return 42; };", f);
 	fclose(f);
 	f = fopen(fsrc, "wb");
-	fputs("export fn foo() i32 = { return 7; };", f);
+	wwtest_fputs("export fn foo() i32 = { return 7; };", f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s/w6c -o %s %s", bin, asmf, src);
diff --git a/test/wcc/640_int_cast_signed.c b/test/wcc/640_int_cast_signed.c
index ed94bfbb..b2e7bb37 100644
--- a/test/wcc/640_int_cast_signed.c
+++ b/test/wcc/640_int_cast_signed.c
@@ -16,6 +16,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -149,7 +150,7 @@ run_driver(const char *driver, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) { runwait(rmcmd); return -1; }
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s build -o %s %s", driver, outbin, src);
diff --git a/test/wcc/650_dot_chain.c b/test/wcc/650_dot_chain.c
index 528f4f05..faf7b556 100644
--- a/test/wcc/650_dot_chain.c
+++ b/test/wcc/650_dot_chain.c
@@ -19,6 +19,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -355,7 +356,7 @@ run_driver(const char *driver, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) { runwait(rmcmd); return -1; }
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s build -o %s %s",
diff --git a/test/wcc/660_field_signed.c b/test/wcc/660_field_signed.c
index c041d3d8..659127d6 100644
--- a/test/wcc/660_field_signed.c
+++ b/test/wcc/660_field_signed.c
@@ -14,6 +14,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -297,7 +298,7 @@ run_driver(const char *driver, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) { runwait(rmcmd); return -1; }
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s build -o %s %s",
diff --git a/test/wcc/670_frame_argcount.c b/test/wcc/670_frame_argcount.c
index 6b1ec2f5..5e0ac6cd 100644
--- a/test/wcc/670_frame_argcount.c
+++ b/test/wcc/670_frame_argcount.c
@@ -18,6 +18,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -294,7 +295,7 @@ run_driver(const char *driver, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) { runwait(rmcmd); return -1; }
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s build -o %s %s", driver, outbin, src);
diff --git a/test/wcc/680_arr_elem_field.c b/test/wcc/680_arr_elem_field.c
index b433b629..8744db66 100644
--- a/test/wcc/680_arr_elem_field.c
+++ b/test/wcc/680_arr_elem_field.c
@@ -24,6 +24,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -153,7 +154,7 @@ run_driver(const char *driver, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) { runwait(rmcmd); return -1; }
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s build -o %s %s",
diff --git a/test/wcc/681_arr_elem_field_write.c b/test/wcc/681_arr_elem_field_write.c
index 37a92883..2f029088 100644
--- a/test/wcc/681_arr_elem_field_write.c
+++ b/test/wcc/681_arr_elem_field_write.c
@@ -22,6 +22,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -504,7 +505,7 @@ run_driver(const char *driver, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) { runwait(rmcmd); return -1; }
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s build -o %s %s", driver, outbin, src);
diff --git a/test/wcc/682_arr_enum_elem.c b/test/wcc/682_arr_enum_elem.c
index d4a08b84..f3966559 100644
--- a/test/wcc/682_arr_enum_elem.c
+++ b/test/wcc/682_arr_enum_elem.c
@@ -71,6 +71,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -162,7 +163,7 @@ run_driver(const char *driver, const struct row *r, int i)
 	mkdir(tmpdir, 0755);
 	FILE *f = fopen(src, "wb");
 	if (!f) { runwait(rmcmd); return -1; }
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s build -o %s %s 2>/dev/null",
@@ -194,7 +195,7 @@ asm_byte_identical(const char *bin, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) return -1;
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s/w6c -o %s %s 2>/dev/null", bin, cs, src);
diff --git a/test/wcc/688_global_arr_elem_field.c b/test/wcc/688_global_arr_elem_field.c
index 4637229e..5855e49e 100644
--- a/test/wcc/688_global_arr_elem_field.c
+++ b/test/wcc/688_global_arr_elem_field.c
@@ -48,6 +48,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 /* want == BYTEID_ONLY: the row cannot LINK/run (a slice-of-struct
  * module global does not data-emit yet — separate gap), so only the
@@ -138,7 +139,7 @@ run_driver(const char *driver, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) { runwait(rmcmd); return -1; }
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s build -o %s %s 2>/dev/null",
@@ -169,7 +170,7 @@ asm_byte_identical(const char *bin, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) return -1;
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s/w6c -o %s %s 2>/dev/null", bin, cs, src);
diff --git a/test/wcc/690_amp_dot.c b/test/wcc/690_amp_dot.c
index e3ec9a47..048881e8 100644
--- a/test/wcc/690_amp_dot.c
+++ b/test/wcc/690_amp_dot.c
@@ -25,6 +25,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -250,7 +251,7 @@ run_driver(const char *driver, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) { runwait(rmcmd); return -1; }
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s build -o %s %s", driver, outbin, src);
diff --git a/test/wcc/691_dot_slice_arg.c b/test/wcc/691_dot_slice_arg.c
index 8de9c1ad..e9c4ff66 100644
--- a/test/wcc/691_dot_slice_arg.c
+++ b/test/wcc/691_dot_slice_arg.c
@@ -34,6 +34,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -228,7 +229,7 @@ run_driver(const char *driver, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) { runwait(rmcmd); return -1; }
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s build -o %s %s", driver, outbin, src);
diff --git a/test/wcc/692_dot_str_chained_arg.c b/test/wcc/692_dot_str_chained_arg.c
index 4eaf218b..35383919 100644
--- a/test/wcc/692_dot_str_chained_arg.c
+++ b/test/wcc/692_dot_str_chained_arg.c
@@ -30,6 +30,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -101,7 +102,7 @@ run_driver(const char *driver, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) { runwait(rmcmd); return -1; }
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s build -o %s %s",
diff --git a/test/wcc/693_dot_tagged_source.c b/test/wcc/693_dot_tagged_source.c
index 02171f91..19ea8f13 100644
--- a/test/wcc/693_dot_tagged_source.c
+++ b/test/wcc/693_dot_tagged_source.c
@@ -43,6 +43,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -316,7 +317,7 @@ run_driver(const char *driver, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) { runwait(rmcmd); return -1; }
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s build -o %s %s", driver, outbin, src);
diff --git a/test/wcc/694_tagged_store_intlit.c b/test/wcc/694_tagged_store_intlit.c
index bd88c5bd..8fdad646 100644
--- a/test/wcc/694_tagged_store_intlit.c
+++ b/test/wcc/694_tagged_store_intlit.c
@@ -50,6 +50,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -277,7 +278,7 @@ run_driver(const char *driver, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) { runwait(rmcmd); return -1; }
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s build -o %s %s", driver, outbin, src);
diff --git a/test/wcc/695_match_bind_struct.c b/test/wcc/695_match_bind_struct.c
index 4ea846e7..e115251b 100644
--- a/test/wcc/695_match_bind_struct.c
+++ b/test/wcc/695_match_bind_struct.c
@@ -45,6 +45,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -223,7 +224,7 @@ run_driver(const char *driver, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) { runwait(rmcmd); return -1; }
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s build -o %s %s",
diff --git a/test/wcc/698_cgreturn_struct.c b/test/wcc/698_cgreturn_struct.c
index a2dde9cf..3166dc22 100644
--- a/test/wcc/698_cgreturn_struct.c
+++ b/test/wcc/698_cgreturn_struct.c
@@ -40,6 +40,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -301,7 +302,7 @@ run_driver(const char *driver, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) { runwait(rmcmd); return -1; }
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s build -o %s %s", driver, outbin, src);
@@ -332,7 +333,7 @@ asm_byte_identical(const char *bin, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) return -1;
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s/w6c -o %s %s 2>/dev/null", bin, cs, src);
diff --git a/test/wcc/700_e2e.c b/test/wcc/700_e2e.c
index 1341d8ff..4386ea21 100644
--- a/test/wcc/700_e2e.c
+++ b/test/wcc/700_e2e.c
@@ -8,6 +8,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -1812,7 +1813,7 @@ main(void)
 		snprintf(rmcmd, sizeof rmcmd, "rm -rf %s", tmpdir);
 
 		FILE *f = fopen(src, "wb");
-		fputs(rows[i].src, f);
+		wwtest_fputs(rows[i].src, f);
 		fclose(f);
 
 		char cmd[1024];
diff --git a/test/wcc/701_cgassign_struct.c b/test/wcc/701_cgassign_struct.c
index 24009eb4..22e29227 100644
--- a/test/wcc/701_cgassign_struct.c
+++ b/test/wcc/701_cgassign_struct.c
@@ -50,6 +50,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -291,7 +292,7 @@ run_driver(const char *driver, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) { runwait(rmcmd); return -1; }
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s build -o %s %s", driver, outbin, src);
@@ -322,7 +323,7 @@ asm_byte_identical(const char *bin, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) return -1;
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s/w6c -o %s %s 2>/dev/null", bin, cs, src);
diff --git a/test/wcc/702_dot_explicit_deref.c b/test/wcc/702_dot_explicit_deref.c
index c3ef26ec..c1a012c4 100644
--- a/test/wcc/702_dot_explicit_deref.c
+++ b/test/wcc/702_dot_explicit_deref.c
@@ -33,6 +33,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -156,7 +157,7 @@ run_driver(const char *driver, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) { runwait(rmcmd); return -1; }
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s build -o %s %s", driver, outbin, src);
@@ -185,7 +186,7 @@ asm_byte_identical(const char *bin, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) return -1;
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s/w6c -o %s %s 2>/dev/null", bin, cs, src);
diff --git a/test/wcc/703_nested_structlit.c b/test/wcc/703_nested_structlit.c
index c594e7cc..33c2310b 100644
--- a/test/wcc/703_nested_structlit.c
+++ b/test/wcc/703_nested_structlit.c
@@ -36,6 +36,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -149,7 +150,7 @@ run_driver(const char *driver, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) { runwait(rmcmd); return -1; }
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s build -o %s %s", driver, outbin, src);
@@ -178,7 +179,7 @@ asm_byte_identical(const char *bin, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) return -1;
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s/w6c -o %s %s 2>/dev/null", bin, cs, src);
diff --git a/test/wcc/704_dot_structlit.c b/test/wcc/704_dot_structlit.c
index 232f96b5..569a0ddc 100644
--- a/test/wcc/704_dot_structlit.c
+++ b/test/wcc/704_dot_structlit.c
@@ -41,6 +41,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -201,7 +202,7 @@ run_driver(const char *driver, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) { runwait(rmcmd); return -1; }
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s build -o %s %s", driver, outbin, src);
@@ -230,7 +231,7 @@ asm_byte_identical(const char *bin, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) return -1;
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s/w6c -o %s %s 2>/dev/null", bin, cs, src);
diff --git a/test/wcc/705_nested_call_rhs.c b/test/wcc/705_nested_call_rhs.c
index 23c589bc..fc00a504 100644
--- a/test/wcc/705_nested_call_rhs.c
+++ b/test/wcc/705_nested_call_rhs.c
@@ -53,6 +53,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -221,7 +222,7 @@ run_driver(const char *driver, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) { runwait(rmcmd); return -1; }
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s build -o %s %s", driver, outbin, src);
@@ -250,7 +251,7 @@ asm_byte_identical(const char *bin, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) return -1;
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s/w6c -o %s %s 2>/dev/null", bin, cs, src);
diff --git a/test/wcc/707_cgreturn_variant_zero.c b/test/wcc/707_cgreturn_variant_zero.c
index 20a0f5a0..a7970e25 100644
--- a/test/wcc/707_cgreturn_variant_zero.c
+++ b/test/wcc/707_cgreturn_variant_zero.c
@@ -65,6 +65,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -310,7 +311,7 @@ run_driver(const char *driver, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) { runwait(rmcmd); return -1; }
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s build -o %s %s", driver, outbin, src);
@@ -341,7 +342,7 @@ asm_byte_identical(const char *bin, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) return -1;
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s/w6c -o %s %s 2>/dev/null", bin, cs, src);
diff --git a/test/wcc/709_localoff_scope.c b/test/wcc/709_localoff_scope.c
index 0e7a760d..ddf68c2e 100644
--- a/test/wcc/709_localoff_scope.c
+++ b/test/wcc/709_localoff_scope.c
@@ -80,6 +80,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -273,7 +274,7 @@ run_driver(const char *driver, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) { runwait(rmcmd); return -1; }
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s build -o %s %s",
diff --git a/test/wcc/710_cast_enum_movl.c b/test/wcc/710_cast_enum_movl.c
index 06eef541..80b97540 100644
--- a/test/wcc/710_cast_enum_movl.c
+++ b/test/wcc/710_cast_enum_movl.c
@@ -110,6 +110,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -347,7 +348,7 @@ run_driver(const char *driver, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) { runwait(rmcmd); return -1; }
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s build -o %s %s 2>/dev/null",
@@ -379,7 +380,7 @@ asm_byte_identical(const char *bin, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) return -1;
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s/w6c -o %s %s 2>/dev/null", bin, cs, src);
diff --git a/test/wcc/711_arrlit_str_full.c b/test/wcc/711_arrlit_str_full.c
index c64eaab9..5b7252d3 100644
--- a/test/wcc/711_arrlit_str_full.c
+++ b/test/wcc/711_arrlit_str_full.c
@@ -47,6 +47,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -216,7 +217,7 @@ run_driver(const char *driver, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) { runwait(rmcmd); return -1; }
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s build -o %s %s", driver, outbin, src);
diff --git a/test/wcc/712_redecl.c b/test/wcc/712_redecl.c
index ef24e463..f2989de0 100644
--- a/test/wcc/712_redecl.c
+++ b/test/wcc/712_redecl.c
@@ -53,6 +53,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -193,7 +194,7 @@ run_row(const char *driver, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) { runwait(rmcmd); return -1; }
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s build -o %s %s >/dev/null 2>&1",
diff --git a/test/wcc/713_struct_field_index.c b/test/wcc/713_struct_field_index.c
index 73261cf6..514ac38e 100644
--- a/test/wcc/713_struct_field_index.c
+++ b/test/wcc/713_struct_field_index.c
@@ -52,6 +52,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -148,7 +149,7 @@ run_driver(const char *driver, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) { runwait(rmcmd); return -1; }
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s build -o %s %s",
diff --git a/test/wcc/714_tagged_return_scratch.c b/test/wcc/714_tagged_return_scratch.c
index a874bb32..f76f0079 100644
--- a/test/wcc/714_tagged_return_scratch.c
+++ b/test/wcc/714_tagged_return_scratch.c
@@ -73,6 +73,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -222,7 +223,7 @@ run_driver(const char *driver, const struct row *r, int i)
 	mkdir(tmpdir, 0755);
 	FILE *f = fopen(src, "wb");
 	if (!f) { runwait(rmcmd); return -1; }
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s build -o %s %s",
diff --git a/test/wcc/715_tagged_widen_f64.c b/test/wcc/715_tagged_widen_f64.c
index b39c342a..2e1f4db3 100644
--- a/test/wcc/715_tagged_widen_f64.c
+++ b/test/wcc/715_tagged_widen_f64.c
@@ -53,6 +53,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -190,7 +191,7 @@ run_driver(const char *driver, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) { runwait(rmcmd); return -1; }
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s build -o %s %s", driver, outbin, src);
diff --git a/test/wcc/716_match_spill_pointer_payload.c b/test/wcc/716_match_spill_pointer_payload.c
index 20961c4e..f72da3f1 100644
--- a/test/wcc/716_match_spill_pointer_payload.c
+++ b/test/wcc/716_match_spill_pointer_payload.c
@@ -42,6 +42,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -144,7 +145,7 @@ run_driver(const char *driver, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) { runwait(rmcmd); return -1; }
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s build -o %s %s", driver, outbin, src);
@@ -175,7 +176,7 @@ asm_byte_identical(const char *bin, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) return -1;
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s/w6c -o %s %s 2>/dev/null", bin, cs, src);
diff --git a/test/wcc/717_struct_byval_param.c b/test/wcc/717_struct_byval_param.c
index 70fc39f0..07762d62 100644
--- a/test/wcc/717_struct_byval_param.c
+++ b/test/wcc/717_struct_byval_param.c
@@ -53,6 +53,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -146,7 +147,7 @@ run_driver(const char *driver, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) { runwait(rmcmd); return -1; }
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s build -o %s %s", driver, outbin, src);
@@ -177,7 +178,7 @@ asm_byte_identical(const char *bin, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) return -1;
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s/w6c -o %s %s 2>/dev/null", bin, cs, src);
diff --git a/test/wcc/718_struct_multi_return_scratch.c b/test/wcc/718_struct_multi_return_scratch.c
index c5819f1c..2d58cce8 100644
--- a/test/wcc/718_struct_multi_return_scratch.c
+++ b/test/wcc/718_struct_multi_return_scratch.c
@@ -65,6 +65,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -232,7 +233,7 @@ run_driver(const char *driver, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) { runwait(rmcmd); return -1; }
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s build -o %s %s",
@@ -308,7 +309,7 @@ asm_byte_identical(const char *bin, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) return -1;
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	int rc = 0;
diff --git a/test/wcc/719_signed_data_emit.c b/test/wcc/719_signed_data_emit.c
index 4709ee10..2607ec35 100644
--- a/test/wcc/719_signed_data_emit.c
+++ b/test/wcc/719_signed_data_emit.c
@@ -27,6 +27,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -52,44 +53,44 @@ static const struct row rows[] = {
 	/* Scalar i8 = -1 → low byte 0xff, then 7 bytes of sign-extension. */
 	{ "i8_neg",  "let x: i8 = -1i8;\n"
 	             "fn main() i32 = { return 0; };\n",
-	  "x",
+	  "main.x",
 	  "\\xff\\xff\\xff\\xff\\xff\\xff\\xff\\xff" },
 	/* Scalar i16 = -2 → 0xfe 0xff then 6 byte sign extension. */
 	{ "i16_neg", "let x: i16 = -2i16;\n"
 	             "fn main() i32 = { return 0; };\n",
-	  "x",
+	  "main.x",
 	  "\\xfe\\xff\\xff\\xff\\xff\\xff\\xff\\xff" },
 	/* Scalar i32 = -100 → 0x9C 0xFF 0xFF 0xFF then 4 byte sign extension. */
 	{ "i32_neg", "let x: i32 = -100i32;\n"
 	             "fn main() i32 = { return 0; };\n",
-	  "x",
+	  "main.x",
 	  "\\x9c\\xff\\xff\\xff\\xff\\xff\\xff\\xff" },
 	/* Scalar i64 = -1000 → 0xfffffffffffffc18 little-endian. */
 	{ "i64_neg", "let x: i64 = -1000i64;\n"
 	             "fn main() i32 = { return 0; };\n",
-	  "x",
+	  "main.x",
 	  "\\x18\\xfc\\xff\\xff\\xff\\xff\\xff\\xff" },
 	/* Array [4]i8 = [1, -2, 3, -4] → 0x01 0xfe 0x03 0xfc. */
 	{ "i8_arr",  "let a: [4]i8 = [1i8, -2i8, 3i8, -4i8];\n"
 	             "fn main() i32 = { return 0; };\n",
-	  "a",
+	  "main.a",
 	  "\\x01\\xfe\\x03\\xfc" },
 	/* Array [4]i16 = [1, -2, 3, -4] → LE16 each. */
 	{ "i16_arr", "let a: [4]i16 = [1i16, -2i16, 3i16, -4i16];\n"
 	             "fn main() i32 = { return 0; };\n",
-	  "a",
+	  "main.a",
 	  "\\x01\\x00\\xfe\\xff\\x03\\x00\\xfc\\xff" },
 	/* Array [3]i32 = [10, -20, 30] → LE32 each. */
 	{ "i32_arr", "let a: [3]i32 = [10i32, -20i32, 30i32];\n"
 	             "fn main() i32 = { return 0; };\n",
-	  "a",
+	  "main.a",
 	  "\\x0a\\x00\\x00\\x00\\xec\\xff\\xff\\xff\\x1e\\x00\\x00\\x00" },
 	/* Array [2]i64 = [100, -200] → LE64 each. Note 100 == 'd' and
 	 * 56 == '8' are printable ASCII so emit_data_byte writes them
 	 * raw rather than as `\xNN`. */
 	{ "i64_arr", "let a: [2]i64 = [100i64, -200i64];\n"
 	             "fn main() i32 = { return 0; };\n",
-	  "a",
+	  "main.a",
 	  "d\\x00\\x00\\x00\\x00\\x00\\x00\\x00"
 	  "8\\xff\\xff\\xff\\xff\\xff\\xff\\xff" },
 };
@@ -128,7 +129,7 @@ emit_s(const char *w6c, const struct row *r, int i, char *out_s, size_t cap)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) return -1;
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s -o %s %s 2>/dev/null", w6c, out_s, src);
diff --git a/test/wcc/720_tagged_call_arg.c b/test/wcc/720_tagged_call_arg.c
index 30f73b1d..d483e696 100644
--- a/test/wcc/720_tagged_call_arg.c
+++ b/test/wcc/720_tagged_call_arg.c
@@ -26,6 +26,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -125,7 +126,7 @@ check_pushdx_before_pushax(const char *spath, const struct row *r)
 	long off = 0;
 	int saw_site = 0;
 	for (;;) {
-		long call = find_after(buf, off, "CALL\tyield_");
+		long call = find_after(buf, off, "CALL\tmain.yield_");
 		if (call < 0) break;
 		saw_site = 1;
 		long pdx = find_after(buf, call, "PUSHQ\tDX");
@@ -162,7 +163,7 @@ emit_s(const char *w6c, const struct row *r, int i, char *out_s, size_t cap)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) return -1;
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s -o %s %s 2>/dev/null", w6c, out_s, src);
diff --git a/test/wcc/721_sret_struct_return.c b/test/wcc/721_sret_struct_return.c
index d9f8e133..79e2d0d0 100644
--- a/test/wcc/721_sret_struct_return.c
+++ b/test/wcc/721_sret_struct_return.c
@@ -41,6 +41,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -144,7 +145,7 @@ emit_s(const char *w6c, const struct row *r, int i, char *out_s, size_t cap)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) return -1;
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s -o %s %s 2>/dev/null", w6c, out_s, src);
@@ -164,8 +165,8 @@ check_leaq_di_before_call(const char *path, const struct row *r)
 	char line[1024];
 	int ok = -1;
 	while (fgets(line, sizeof line, f)) {
-		if (strstr(line, "CALL\tmk(SB)")
-		    || strstr(line, "CALL mk(SB)")) {
+		if (strstr(line, "CALL\tmain.mk(SB)")
+		    || strstr(line, "CALL main.mk(SB)")) {
 			if (strstr(prev, "LEAQ\t")
 			    && strstr(prev, "(BP), DI")) {
 				ok = 0;
@@ -199,7 +200,7 @@ check_movq_bp_ax_before_ret(const char *path, const struct row *r)
 	int ok = -1;
 	while (fgets(line, sizeof line, f)) {
 		if (!in_mk) {
-			if (strstr(line, "TEXT mk,") || strstr(line, "TEXT\tmk,"))
+			if (strstr(line, "TEXT main.mk,") || strstr(line, "TEXT\tmain.mk,"))
 				in_mk = 1;
 			continue;
 		}
@@ -241,15 +242,15 @@ check_movq_bp_di_before_inner_call(const char *path, const struct row *r)
 	int ok = -1;
 	while (fgets(line, sizeof line, f)) {
 		if (!in_mk) {
-			if (strstr(line, "TEXT mk,")
-			    || strstr(line, "TEXT\tmk,"))
+			if (strstr(line, "TEXT main.mk,")
+			    || strstr(line, "TEXT\tmain.mk,"))
 				in_mk = 1;
 			strncpy(prev, line, sizeof prev - 1);
 			prev[sizeof prev - 1] = '\0';
 			continue;
 		}
-		if (strstr(line, "CALL\tinner(SB)")
-		    || strstr(line, "CALL inner(SB)")) {
+		if (strstr(line, "CALL\tmain.inner(SB)")
+		    || strstr(line, "CALL main.inner(SB)")) {
 			if (strstr(prev, "MOVQ\t")
 			    && strstr(prev, "(BP), DI")
 			    && !strstr(prev, "LEAQ"))
@@ -283,8 +284,8 @@ check_no_movq_ax_bp_after_call(const char *path, const struct row *r)
 	int ok = 0;
 	while (fgets(line, sizeof line, f)) {
 		if (!seen_call) {
-			if (strstr(line, "CALL\tmk(SB)")
-			    || strstr(line, "CALL mk(SB)")) {
+			if (strstr(line, "CALL\tmain.mk(SB)")
+			    || strstr(line, "CALL main.mk(SB)")) {
 				seen_call = 1;
 			}
 			continue;
diff --git a/test/wcc/722_match_slice_variant.c b/test/wcc/722_match_slice_variant.c
index 2db91d16..dadc4452 100644
--- a/test/wcc/722_match_slice_variant.c
+++ b/test/wcc/722_match_slice_variant.c
@@ -25,6 +25,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -107,7 +108,7 @@ emit_s(const char *w6c, const struct row *r, int i, char *out_s, size_t cap)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) return -1;
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s -o %s %s 2>/dev/null", w6c, out_s, src);
diff --git a/test/wcc/723_composite_call_arg.c b/test/wcc/723_composite_call_arg.c
index 5b3388d2..680f85f7 100644
--- a/test/wcc/723_composite_call_arg.c
+++ b/test/wcc/723_composite_call_arg.c
@@ -24,6 +24,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -84,7 +85,7 @@ check_three_push_after_call(const char *spath, const struct row *r)
 	char buf[1 << 16];
 	if (slurp(spath, buf, sizeof buf) < 0) return -1;
 
-	long call = find_after(buf, 0, "CALL\tview");
+	long call = find_after(buf, 0, "CALL\tmain.view");
 	if (call < 0) {
 		fprintf(stderr, "row[%s]: no CALL view site\n", r->label);
 		return -1;
@@ -135,7 +136,7 @@ emit_s(const char *w6c, const struct row *r, int i, char *out_s, size_t cap)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) return -1;
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s -o %s %s 2>/dev/null", w6c, out_s, src);
diff --git a/test/wcc/724_letdecl_zeroinit.c b/test/wcc/724_letdecl_zeroinit.c
index 514a1f61..0410f346 100644
--- a/test/wcc/724_letdecl_zeroinit.c
+++ b/test/wcc/724_letdecl_zeroinit.c
@@ -29,6 +29,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -79,7 +80,7 @@ check_movq_zero_present(const char *spath, const struct row *r)
 	char buf[1 << 16];
 	if (slurp(spath, buf, sizeof buf) < 0) return -1;
 
-	const char *body = strstr(buf, "TEXT produce");
+	const char *body = strstr(buf, "TEXT main.produce");
 	if (!body) {
 		fprintf(stderr, "row[%s]: no TEXT produce label\n", r->label);
 		return -1;
@@ -112,7 +113,7 @@ emit_s(const char *w6c, const struct row *r, int i, char *out_s, size_t cap)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) return -1;
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s -o %s %s 2>/dev/null", w6c, out_s, src);
diff --git a/test/wcc/725_nested_if_labels.c b/test/wcc/725_nested_if_labels.c
index b3bedb7d..915bbc96 100644
--- a/test/wcc/725_nested_if_labels.c
+++ b/test/wcc/725_nested_if_labels.c
@@ -30,6 +30,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -76,7 +77,7 @@ emit_s(const char *w6c, const struct row *r, int i, char *out_s, size_t cap)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) return -1;
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s -o %s %s 2>/dev/null", w6c, out_s, src);
diff --git a/test/wcc/726_alias_leaf_collision.c b/test/wcc/726_alias_leaf_collision.c
index 74298f44..e3186bde 100644
--- a/test/wcc/726_alias_leaf_collision.c
+++ b/test/wcc/726_alias_leaf_collision.c
@@ -30,6 +30,7 @@
 #include <string.h>
 #include <unistd.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -97,7 +98,7 @@ emit_s(const char *w6c, const struct row *r, int i, char *out_s, size_t cap)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) return -1;
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s -o %s %s 2>/dev/null", w6c, out_s, src);
@@ -172,7 +173,7 @@ check_movsxd_kept(const char *spath, const struct row *r, const char *stage)
 		    r->label, stage, spath);
 		return -1;
 	}
-	const char *fn = strstr(buf, "TEXT promote");
+	const char *fn = strstr(buf, "TEXT main.promote");
 	if (!fn) {
 		fprintf(stderr, "row[%s][%s]: no TEXT promote in %s\n",
 		    r->label, stage, spath);
diff --git a/test/wcc/729_empty_alloc_infer.c b/test/wcc/729_empty_alloc_infer.c
index 9d53984b..6047b8ab 100644
--- a/test/wcc/729_empty_alloc_infer.c
+++ b/test/wcc/729_empty_alloc_infer.c
@@ -36,6 +36,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -131,7 +132,7 @@ run_row(const char *driver, const struct row *r, int i)
 
 		FILE *f = fopen(src, "wb");
 		if (!f) { runwait(rmcmd); return -1; }
-		fputs(r->src, f);
+		wwtest_fputs(r->src, f);
 		fclose(f);
 
 		snprintf(cmd, sizeof cmd,
@@ -155,7 +156,7 @@ run_row(const char *driver, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) return -1;
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s run %s >/dev/null 2>&1", driver, src);
diff --git a/test/wcc/730_sret_narrow_field.c b/test/wcc/730_sret_narrow_field.c
index ce816eaa..0ced1b29 100644
--- a/test/wcc/730_sret_narrow_field.c
+++ b/test/wcc/730_sret_narrow_field.c
@@ -28,6 +28,7 @@
 #include <string.h>
 #include <unistd.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -112,7 +113,7 @@ emit_s(const char *w6c, const struct row *r, int i, char *out_s, size_t cap)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) return -1;
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s -o %s %s 2>/dev/null", w6c, out_s, src);
@@ -144,8 +145,8 @@ check_narrow_mov(const char *path, const struct row *r)
 	(void)load_needle;
 	while (fgets(line, sizeof line, f)) {
 		if (!in_mk) {
-			if (strstr(line, "TEXT mk,")
-			    || strstr(line, "TEXT\tmk,"))
+			if (strstr(line, "TEXT main.mk,")
+			    || strstr(line, "TEXT\tmain.mk,"))
 				in_mk = 1;
 			continue;
 		}
@@ -188,8 +189,8 @@ check_no_movq_at_off(const char *path, const struct row *r)
 	int bad = 0;
 	while (fgets(line, sizeof line, f)) {
 		if (!in_mk) {
-			if (strstr(line, "TEXT mk,")
-			    || strstr(line, "TEXT\tmk,"))
+			if (strstr(line, "TEXT main.mk,")
+			    || strstr(line, "TEXT\tmain.mk,"))
 				in_mk = 1;
 			continue;
 		}
diff --git a/test/wcc/732_def_const_fold.c b/test/wcc/732_def_const_fold.c
index 971f2d46..d2459ccd 100644
--- a/test/wcc/732_def_const_fold.c
+++ b/test/wcc/732_def_const_fold.c
@@ -44,6 +44,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -133,7 +134,7 @@ run_driver(const char *driver, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) { runwait(rmcmd); return -1; }
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	/* timeout 180 per repo convention (990-997); test/run does not bound
@@ -187,7 +188,7 @@ asm_byte_identical(const char *bin, const char *src, const char *label, int i)
 
 	FILE *f = fopen(wwsrc, "wb");
 	if (!f) return -1;
-	fputs(src, f);
+	wwtest_fputs(src, f);
 	fclose(f);
 
 	char w6c[640], w6c_ww[640];
@@ -255,7 +256,7 @@ xmod_fold_present(const char *w6c, const char *stage)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) return -1;
-	fputs(xmod_src, f);
+	wwtest_fputs(xmod_src, f);
 	fclose(f);
 
 	if (emit_s(w6c, src, s, sizeof s) != 0) {
@@ -316,7 +317,7 @@ compile_fails(const char *w6c, const struct failrow *r, const char *stage, int i
 
 	FILE *f = fopen(src, "wb");
 	if (!f) return -1;
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	/* A regressed depth guard would HANG the cycle rows rather than fail
diff --git a/test/wcc/736_cstage_label_ssot.c b/test/wcc/736_cstage_label_ssot.c
index 475aeef8..fd71fa08 100644
--- a/test/wcc/736_cstage_label_ssot.c
+++ b/test/wcc/736_cstage_label_ssot.c
@@ -35,6 +35,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -94,7 +95,7 @@ emit_s(const char *w6c, const char *src_text, int i, char *out_s, size_t cap)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) return -1;
-	fputs(src_text, f);
+	wwtest_fputs(src_text, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s -o %s %s 2>/dev/null", w6c, out_s, src);
diff --git a/test/wcc/739_chained_index.c b/test/wcc/739_chained_index.c
index 69ee8b2d..c21bd26b 100644
--- a/test/wcc/739_chained_index.c
+++ b/test/wcc/739_chained_index.c
@@ -32,6 +32,7 @@
 #include <string.h>
 #include <unistd.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -96,7 +97,7 @@ emit_s(const char *w6c, const struct row *r, int i, char *out_s, size_t cap)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) return -1;
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s -o %s %s 2>/dev/null", w6c, out_s, src);
@@ -117,7 +118,7 @@ check_loadmov(const char *spath, const struct row *r, const char *stage)
 		    r->label, stage, spath);
 		return -1;
 	}
-	const char *fn = strstr(buf, "TEXT probe");
+	const char *fn = strstr(buf, "TEXT main.probe");
 	if (!fn) {
 		fprintf(stderr,
 		    "row[%s][%s]: no TEXT probe in %s\n",
@@ -149,7 +150,7 @@ check_inner_scale_only(const char *spath, const struct row *r,
 {
 	char buf[1 << 14];
 	if (slurp(spath, buf, sizeof buf) < 0) return -1;
-	const char *fn = strstr(buf, "TEXT probe");
+	const char *fn = strstr(buf, "TEXT main.probe");
 	if (!fn) return -1;
 	const char *ret = strstr(fn, "\tRET\n");
 	if (!ret) ret = fn + strlen(fn);
diff --git a/test/wcc/740_chained_write.c b/test/wcc/740_chained_write.c
index e7177454..20cd3ba5 100644
--- a/test/wcc/740_chained_write.c
+++ b/test/wcc/740_chained_write.c
@@ -34,6 +34,7 @@
 #include <string.h>
 #include <unistd.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -98,7 +99,7 @@ emit_s(const char *w6c, const struct row *r, int i, char *out_s, size_t cap)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) return -1;
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s -o %s %s 2>/dev/null", w6c, out_s, src);
@@ -119,7 +120,7 @@ check_storemov(const char *spath, const struct row *r, const char *stage)
 		    r->label, stage, spath);
 		return -1;
 	}
-	const char *fn = strstr(buf, "TEXT probe");
+	const char *fn = strstr(buf, "TEXT main.probe");
 	if (!fn) {
 		fprintf(stderr,
 		    "row[%s][%s]: no TEXT probe in %s\n",
@@ -164,7 +165,7 @@ check_inner_scale_only(const char *spath, const struct row *r,
 {
 	char buf[1 << 14];
 	if (slurp(spath, buf, sizeof buf) < 0) return -1;
-	const char *fn = strstr(buf, "TEXT probe");
+	const char *fn = strstr(buf, "TEXT main.probe");
 	if (!fn) return -1;
 	const char *ret = strstr(fn, "\tRET\n");
 	if (!ret) ret = fn + strlen(fn);
diff --git a/test/wcc/741_dotbase_chained.c b/test/wcc/741_dotbase_chained.c
index 337a1a1e..b002d2b5 100644
--- a/test/wcc/741_dotbase_chained.c
+++ b/test/wcc/741_dotbase_chained.c
@@ -46,6 +46,7 @@
 #include <string.h>
 #include <unistd.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -126,7 +127,7 @@ emit_s(const char *w6c, const struct row *r, int i, char *out_s, size_t cap)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) return -1;
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s -o %s %s 2>/dev/null", w6c, out_s, src);
@@ -146,7 +147,7 @@ check_probe(const char *spath, const struct row *r, const char *stage)
 		    r->label, stage, spath);
 		return -1;
 	}
-	const char *fn = strstr(buf, "TEXT probe");
+	const char *fn = strstr(buf, "TEXT main.probe");
 	if (!fn) {
 		fprintf(stderr,
 		    "row[%s][%s]: no TEXT probe in %s\n",
diff --git a/test/wcc/743_variadic_pack.c b/test/wcc/743_variadic_pack.c
index b9e4c4fa..d02f1f35 100644
--- a/test/wcc/743_variadic_pack.c
+++ b/test/wcc/743_variadic_pack.c
@@ -25,6 +25,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -67,7 +68,7 @@ check_caller_stores(const char *spath)
 	char buf[1 << 16];
 	if (slurp(spath, buf, sizeof buf) < 0) return -1;
 
-	const char *body = strstr(buf, "TEXT main");
+	const char *body = strstr(buf, "TEXT main,");
 	if (!body) {
 		fprintf(stderr, "variadic_pack: no TEXT main label\n");
 		return -1;
@@ -118,7 +119,7 @@ emit_s(const char *w6c, char *out_s, size_t cap, int tag)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) return -1;
-	fputs(src_text, f);
+	wwtest_fputs(src_text, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s -o %s %s 2>/dev/null", w6c, out_s, src);
diff --git a/test/wcc/744_letcopy_struct.c b/test/wcc/744_letcopy_struct.c
index ed8cbe6a..1f35990c 100644
--- a/test/wcc/744_letcopy_struct.c
+++ b/test/wcc/744_letcopy_struct.c
@@ -31,6 +31,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -200,7 +201,7 @@ check_copy_loads(const char *spath, const struct row *r)
 	static char buf[1 << 16];
 	if (slurp(spath, buf, sizeof buf) < 0) return -1;
 
-	const char *body = strstr(buf, "TEXT produce");
+	const char *body = strstr(buf, "TEXT main.produce");
 	if (!body) {
 		fprintf(stderr, "row[%s]: no TEXT produce label in %s\n",
 		    r->label, spath);
@@ -233,7 +234,7 @@ emit_s(const char *w6c, const struct row *r, int i, int stage,
 
 	FILE *f = fopen(src, "wb");
 	if (!f) return -1;
-	fputs(r->asm_src, f);
+	wwtest_fputs(r->asm_src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s -o %s %s 2>/dev/null", w6c, out_s, src);
@@ -257,7 +258,7 @@ run_driver(const char *driver, const struct row *r, int i, int stage)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) { runwait(rmcmd); return -1; }
-	fputs(r->run_src, f);
+	wwtest_fputs(r->run_src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s build -o %s %s 2>/dev/null",
diff --git a/test/wcc/754_slice_of_slice_index.c b/test/wcc/754_slice_of_slice_index.c
index d65938d9..1253f0fa 100644
--- a/test/wcc/754_slice_of_slice_index.c
+++ b/test/wcc/754_slice_of_slice_index.c
@@ -51,6 +51,7 @@
 #include <string.h>
 #include <unistd.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -111,7 +112,7 @@ emit_s(const char *w6c, const struct row *r, int i, char *out_s, size_t cap)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) return -1;
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s -o %s %s 2>/dev/null", w6c, out_s, src);
@@ -129,7 +130,7 @@ check_stride(const char *spath, const struct row *r, const char *stage)
 		    r->label, stage, spath);
 		return -1;
 	}
-	const char *fn = strstr(buf, "TEXT probe");
+	const char *fn = strstr(buf, "TEXT main.probe");
 	if (!fn) {
 		fprintf(stderr,
 		    "row[%s][%s]: no TEXT probe in %s\n",
diff --git a/test/wcc/755_amp_dot_idx.c b/test/wcc/755_amp_dot_idx.c
index 60608103..f6563ded 100644
--- a/test/wcc/755_amp_dot_idx.c
+++ b/test/wcc/755_amp_dot_idx.c
@@ -61,6 +61,7 @@
 #include <string.h>
 #include <unistd.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -143,7 +144,7 @@ emit_s(const char *w6c, const struct row *r, int i, char *out_s, size_t cap)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) return -1;
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s -o %s %s 2>/dev/null", w6c, out_s, src);
@@ -161,7 +162,7 @@ check_stride(const char *spath, const struct row *r, const char *stage)
 		    r->label, stage, spath);
 		return -1;
 	}
-	const char *fn = strstr(buf, "TEXT probe");
+	const char *fn = strstr(buf, "TEXT main.probe");
 	if (!fn) {
 		fprintf(stderr,
 		    "row[%s][%s]: no TEXT probe in %s\n",
diff --git a/test/wcc/757_letbind_void_bang_void.c b/test/wcc/757_letbind_void_bang_void.c
index f57f245a..ce970a0d 100644
--- a/test/wcc/757_letbind_void_bang_void.c
+++ b/test/wcc/757_letbind_void_bang_void.c
@@ -38,6 +38,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -121,7 +122,7 @@ run_driver(const char *driver, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) { runwait(rmcmd); return -1; }
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s build -o %s %s", driver, outbin, src);
@@ -152,7 +153,7 @@ asm_byte_identical(const char *bin, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) return -1;
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s/w6c -o %s %s 2>/dev/null", bin, cs, src);
diff --git a/test/wcc/759_check_enum_fold.c b/test/wcc/759_check_enum_fold.c
index 815e1073..5ed3a4d4 100644
--- a/test/wcc/759_check_enum_fold.c
+++ b/test/wcc/759_check_enum_fold.c
@@ -27,6 +27,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -158,7 +159,7 @@ run_driver(const char *driver, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) { runwait(rmcmd); return -1; }
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s build -o %s %s 2>/dev/null",
@@ -191,7 +192,7 @@ asm_byte_identical(const char *bin, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) return -1;
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s/w6c -o %s %s 2>/dev/null", bin, cs, src);
diff --git a/test/wcc/760_def_widen_const.c b/test/wcc/760_def_widen_const.c
index d30fc06c..28cf1f21 100644
--- a/test/wcc/760_def_widen_const.c
+++ b/test/wcc/760_def_widen_const.c
@@ -42,6 +42,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -107,7 +108,7 @@ run_driver(const char *driver, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) { runwait(rmcmd); return -1; }
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	/* timeout 180 per repo convention; test/run does not bound
@@ -151,7 +152,7 @@ asm_byte_identical(const char *bin, const char *src, const char *label, int i)
 
 	FILE *f = fopen(wwsrc, "wb");
 	if (!f) return -1;
-	fputs(src, f);
+	wwtest_fputs(src, f);
 	fclose(f);
 
 	char w6c[640], w6c_ww[640];
@@ -212,7 +213,7 @@ cstage_narrow_fails(const char *w6c)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) return -1;
-	fputs(narrow_src, f);
+	wwtest_fputs(narrow_src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "timeout 180 %s -o %s %s 2>/dev/null",
diff --git a/test/wcc/761_inferred_struct_arg_push.c b/test/wcc/761_inferred_struct_arg_push.c
index 4abb43c0..1bfd427a 100644
--- a/test/wcc/761_inferred_struct_arg_push.c
+++ b/test/wcc/761_inferred_struct_arg_push.c
@@ -62,6 +62,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -208,7 +209,7 @@ run_driver(const char *driver, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) { runwait(rmcmd); return -1; }
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	/* timeout 180 per repo convention (cf. 760); test/run does not
@@ -243,7 +244,7 @@ asm_byte_identical(const char *bin, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) return -1;
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "timeout 180 %s/w6c -o %s %s 2>/dev/null",
diff --git a/test/wcc/762_struct_abi_size.c b/test/wcc/762_struct_abi_size.c
index 5d4a9e52..ed415e33 100644
--- a/test/wcc/762_struct_abi_size.c
+++ b/test/wcc/762_struct_abi_size.c
@@ -46,6 +46,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -141,7 +142,7 @@ run_driver(const char *driver, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) { runwait(rmcmd); return -1; }
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	/* timeout 180 per repo convention (cf. 760, 761); test/run does
@@ -176,7 +177,7 @@ asm_byte_identical(const char *bin, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) return -1;
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "timeout 180 %s/w6c -o %s %s 2>/dev/null",
diff --git a/test/wcc/763_typeeq_fn_ast.c b/test/wcc/763_typeeq_fn_ast.c
index a871d3d5..6041b07e 100644
--- a/test/wcc/763_typeeq_fn_ast.c
+++ b/test/wcc/763_typeeq_fn_ast.c
@@ -57,6 +57,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -181,7 +182,7 @@ run_driver(const char *driver, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) { runwait(rmcmd); return -1; }
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	/* timeout 180 per repo convention (cf. 761, 762); test/run does
diff --git a/test/wcc/764_amp_fn_ident.c b/test/wcc/764_amp_fn_ident.c
index c4b39677..d752d783 100644
--- a/test/wcc/764_amp_fn_ident.c
+++ b/test/wcc/764_amp_fn_ident.c
@@ -60,6 +60,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -99,7 +100,7 @@ static const struct row rows[] = {
 	  "    return 0;\n"
 	  "};\n",
 	  NULL, NULL,
-	  "LEAQ\tadd1(SB)",
+	  "LEAQ\tmain.add1(SB)",
 	  STAGE_CS | STAGE_WW },
 	{ "branched_callee",
 	  "fn aa(x: i32) i32 = { return x; };\n"
@@ -111,7 +112,7 @@ static const struct row rows[] = {
 	  "    return 0;\n"
 	  "};\n",
 	  NULL, NULL,
-	  "LEAQ\tbb(SB)",
+	  "LEAQ\tmain.bb(SB)",
 	  STAGE_CS | STAGE_WW },
 	{ "alias_chain",
 	  "fn add1(x: i32) i32 = { return x + 1; };\n"
@@ -121,7 +122,7 @@ static const struct row rows[] = {
 	  "    return 0;\n"
 	  "};\n",
 	  NULL, NULL,
-	  "LEAQ\tadd1(SB)",
+	  "LEAQ\tmain.add1(SB)",
 	  STAGE_CS | STAGE_WW },
 	{ "fn_with_args",
 	  "fn many(a: i32, b: i64, p: *i32) i64 = { return b; };\n"
@@ -130,7 +131,7 @@ static const struct row rows[] = {
 	  "    return 0;\n"
 	  "};\n",
 	  NULL, NULL,
-	  "LEAQ\tmany(SB)",
+	  "LEAQ\tmain.many(SB)",
 	  STAGE_CS | STAGE_WW },
 	{ "fn_tuple_return",
 	  "fn pair() (i64, str) = { return (7: i64, \"x\"); };\n"
@@ -139,7 +140,7 @@ static const struct row rows[] = {
 	  "    return 0;\n"
 	  "};\n",
 	  NULL, NULL,
-	  "LEAQ\tpair(SB)",
+	  "LEAQ\tmain.pair(SB)",
 	  STAGE_CS | STAGE_WW },
 	/* Cross-mod: cstage emits the LEAQ via N_DOT TK_AMP (already
 	 * working pre-#180). Wwstage bails asserttyped on the same
@@ -156,6 +157,7 @@ static const struct row rows[] = {
 	  "    return 0;\n"
 	  "};\n",
 	  "wcamffn764mod",
+	  "package wcamffn764mod;\n"
 	  "export fn somefn(x: i32) i32 = { return x + 1; };\n",
 	  "LEAQ\twcamffn764mod.somefn(SB)",
 	  STAGE_CS },
@@ -181,13 +183,13 @@ write_sources(const struct row *r, char *src, size_t srcsz,
 		mkdir(moddir, 0755);
 		FILE *mf = fopen(modfile, "wb");
 		if (!mf) return -1;
-		fputs(r->modsrc, mf);
+		wwtest_fputs(r->modsrc, mf);
 		fclose(mf);
 	}
 
 	FILE *f = fopen(src, "wb");
 	if (!f) return -1;
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 	return 0;
 }
diff --git a/test/wcc/765_star_fn_deref.c b/test/wcc/765_star_fn_deref.c
index 35bacfbb..e5bdf75d 100644
--- a/test/wcc/765_star_fn_deref.c
+++ b/test/wcc/765_star_fn_deref.c
@@ -60,6 +60,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -144,7 +145,7 @@ write_source(const char *src_path, const char *src)
 {
 	FILE *f = fopen(src_path, "wb");
 	if (!f) return -1;
-	fputs(src, f);
+	wwtest_fputs(src, f);
 	fclose(f);
 	return 0;
 }
diff --git a/test/wcc/766_star_fn_deref_call.c b/test/wcc/766_star_fn_deref_call.c
index f641d4d9..0ecdfba4 100644
--- a/test/wcc/766_star_fn_deref_call.c
+++ b/test/wcc/766_star_fn_deref_call.c
@@ -52,6 +52,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -132,7 +133,7 @@ write_source(const char *src_path, const char *src)
 {
 	FILE *f = fopen(src_path, "wb");
 	if (!f) return -1;
-	fputs(src, f);
+	wwtest_fputs(src, f);
 	fclose(f);
 	return 0;
 }
diff --git a/test/wcc/767_match_variant_dispatch.c b/test/wcc/767_match_variant_dispatch.c
index 9b069f5e..85ace00c 100644
--- a/test/wcc/767_match_variant_dispatch.c
+++ b/test/wcc/767_match_variant_dispatch.c
@@ -78,6 +78,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -182,7 +183,7 @@ write_source(const char *src_path, const char *src)
 {
 	FILE *f = fopen(src_path, "wb");
 	if (!f) return -1;
-	fputs(src, f);
+	wwtest_fputs(src, f);
 	fclose(f);
 	return 0;
 }
diff --git a/test/wcc/782_strict_package.c b/test/wcc/782_strict_package.c
new file mode 100644
index 00000000..21d52855
--- /dev/null
+++ b/test/wcc/782_strict_package.c
@@ -0,0 +1,163 @@
+/*
+ * 782_strict_package — #24a strict-package gate, BOTH stages (w6c + w6c_ww).
+ *
+ * Every primary section must open with a `package` clause; a missing clause
+ * on the first real decl is a hard error ("missing package clause"). An
+ * imported (`//ww:module <path>`) or sep primary-reset region carries its
+ * identity out-of-band and is exempt; an in-section `package` clause then
+ * ASSERTS — its leaf must equal the path's last component ("package <x>
+ * does not match import path <p>"). A bare `//ww:module-reset` opens a fresh
+ * primary section that must itself re-declare a clause.
+ *
+ * Rule-10: every row runs on cstage `w6c` AND wwstage `w6c_ww`; both must
+ * agree (accept/reject identically; diagnostic text differs by stage —
+ * cstage `errorf` carries a position, wwstage `errmsg` is terser — so the
+ * check is on a shared substring, not the whole line). Reject rows feed RAW
+ * source: the `package` clause IS the unit under test, so there is no
+ * auto-prepend here (unlike the migrated codegen fixtures).
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+
+static int
+runwait(const char *cmd)
+{
+	int rc = system(cmd);
+	if (rc == -1) return -1;
+	if (WIFEXITED(rc)) return WEXITSTATUS(rc);
+	return 1;
+}
+
+static int
+file_contains(const char *path, const char *needle)
+{
+	FILE *f = fopen(path, "r");
+	if (!f) return 0;
+	char line[4096];
+	int found = 0;
+	while (fgets(line, sizeof line, f))
+		if (strstr(line, needle)) { found = 1; break; }
+	fclose(f);
+	return found;
+}
+
+struct row {
+	const char *label;
+	const char *src;
+	int accept;		/* 1 = must compile clean; 0 = must reject */
+	const char *diag;	/* reject: required stderr substring (NULL on accept) */
+};
+
+static const struct row rows[] = {
+	/* 1: a `package main;` executable section. */
+	{ "pkg_main_accept",
+	  "package main;\nexport fn main() i32 = { return 0; };\n",
+	  1, NULL },
+	/* 2: no clause → hard error on the first decl. */
+	{ "no_clause_reject",
+	  "export fn main() i32 = { return 0; };\n",
+	  0, "missing package clause" },
+	/* 3: imported region — the clause leaf matches the path leaf. */
+	{ "module_leaf_match_accept",
+	  "//ww:module foo\npackage foo;\nexport fn x() i32 = { return 0; };\n",
+	  1, NULL },
+	/* 4: imported region — the clause leaf mismatches the path. */
+	{ "module_leaf_mismatch_reject",
+	  "//ww:module foo\npackage bar;\nexport fn x() i32 = { return 0; };\n",
+	  0, "does not match import path" },
+	/* 5: a comment-only file declares nothing, so no clause is required. */
+	{ "comment_only_accept",
+	  "// just a comment, no decls\n",
+	  1, NULL },
+	/* 6: a bare `//ww:module-reset` opens a fresh primary section; the
+	 * clause-less second section is rejected (the #84/#24a boundary). */
+	{ "reset_second_section_reject",
+	  "package main;\nexport fn a() i32 = { return 0; };\n"
+	  "//ww:module-reset\nexport fn b() i32 = { return 0; };\n",
+	  0, "missing package clause" },
+	{ NULL, NULL, 0, NULL },
+};
+
+/* Compile r->src with `stage` (a w6c-family binary); verify accept/reject
+ * and, on reject, the diagnostic substring. Returns 0 on success. */
+static int
+check_stage(const char *stage, const char *tag, const struct row *r,
+    const char *tmpdir)
+{
+	char src[256], sout[256], errf[256], cmd[2048];
+	snprintf(src,  sizeof src,  "%s/sp_%s.ww", tmpdir, r->label);
+	snprintf(sout, sizeof sout, "%s/sp_%s.s",  tmpdir, r->label);
+	snprintf(errf, sizeof errf, "%s/sp_%s.err", tmpdir, r->label);
+
+	FILE *f = fopen(src, "wb");
+	if (!f) { fprintf(stderr, "782 FAIL: write %s\n", src); return 1; }
+	fputs(r->src, f);
+	fclose(f);
+
+	snprintf(cmd, sizeof cmd, "%s -o %s %s 2>%s", stage, sout, src, errf);
+	int rc = runwait(cmd);
+
+	if (r->accept) {
+		if (rc != 0) {
+			fprintf(stderr, "782 FAIL: [%s][%s] expected ACCEPT, "
+			    "rejected (rc=%d)\n", r->label, tag, rc);
+			return 1;
+		}
+		return 0;
+	}
+	if (rc == 0) {
+		fprintf(stderr, "782 FAIL: [%s][%s] expected REJECT, "
+		    "accepted\n", r->label, tag);
+		return 1;
+	}
+	if (!file_contains(errf, r->diag)) {
+		fprintf(stderr, "782 FAIL: [%s][%s] rejected but no `%s` "
+		    "on stderr\n", r->label, tag, r->diag);
+		return 1;
+	}
+	return 0;
+}
+
+int
+main(void)
+{
+	const char *bin = getenv("BIN");
+	if (!bin) bin = "out/bin";
+	char absbin[1024];
+	if (bin[0] != '/') {
+		char cwd[1024];
+		if (getcwd(cwd, sizeof cwd) == NULL) return 1;
+		snprintf(absbin, sizeof absbin, "%s/%s", cwd, bin);
+		bin = absbin;
+	}
+
+	char cs[1100], ww[1100], tmpdir[64], rmcmd[160];
+	snprintf(cs, sizeof cs, "%s/w6c", bin);
+	snprintf(ww, sizeof ww, "%s/w6c_ww", bin);
+	snprintf(tmpdir, sizeof tmpdir, "/tmp/sp782_%d", getpid());
+	mkdir(tmpdir, 0755);
+	snprintf(rmcmd, sizeof rmcmd, "rm -rf %s", tmpdir);
+
+	/* wwstage twin is gated on its presence (rule 14 / 993 pattern). */
+	int have_ww = (access(ww, X_OK) == 0);
+
+	int fail = 0;
+	for (int i = 0; rows[i].label; i++) {
+		fail += check_stage(cs, "cs", &rows[i], tmpdir);
+		if (have_ww)
+			fail += check_stage(ww, "ww", &rows[i], tmpdir);
+	}
+
+	runwait(rmcmd);
+	if (fail) {
+		fprintf(stderr, "782: %d check(s) failed\n", fail);
+		return 1;
+	}
+	printf("strict_package: 6 rows (accept/reject + leaf-assert + bare-reset) "
+	    "agree on cstage w6c%s (#24a)\n", have_ww ? " and wwstage w6c_ww" : "");
+	return 0;
+}
diff --git a/test/wcc/800_ffi.c b/test/wcc/800_ffi.c
index f56b09d8..c0eb0861 100644
--- a/test/wcc/800_ffi.c
+++ b/test/wcc/800_ffi.c
@@ -11,6 +11,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
+#include "wwtestpkg.h"
 
 static char *
 run6c(const char *bin, const char *src)
@@ -18,7 +19,7 @@ run6c(const char *bin, const char *src)
 	char path[64];
 	snprintf(path, sizeof path, "/tmp/wwffi_%d.ww", getpid());
 	FILE *f = fopen(path, "wb");
-	fputs(src, f);
+	wwtest_fputs(src, f);
 	fclose(f);
 
 	char cmd[512];
diff --git a/test/wcc/810_dyn.c b/test/wcc/810_dyn.c
index 624285f2..0e752d8f 100644
--- a/test/wcc/810_dyn.c
+++ b/test/wcc/810_dyn.c
@@ -20,6 +20,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -136,7 +137,7 @@ main(void)
 		snprintf(rmcmd, sizeof rmcmd, "rm -rf %s", tmpdir);
 
 		FILE *f = fopen(src, "wb");
-		fputs(rows[i].src, f);
+		wwtest_fputs(rows[i].src, f);
 		fclose(f);
 
 		char cmd[1024];
diff --git a/test/wcc/940_global_sret_run.c b/test/wcc/940_global_sret_run.c
index 4fa8b0e2..970443fe 100644
--- a/test/wcc/940_global_sret_run.c
+++ b/test/wcc/940_global_sret_run.c
@@ -28,6 +28,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -171,7 +172,7 @@ run_driver(const char *driver, const struct row *r, const char *dir,
 
 	FILE *f = fopen(src, "wb");
 	if (!f) return -1;
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd,
diff --git a/test/wcc/940_str_forrange_loopvar_run.c b/test/wcc/940_str_forrange_loopvar_run.c
index 223db149..292de5ff 100644
--- a/test/wcc/940_str_forrange_loopvar_run.c
+++ b/test/wcc/940_str_forrange_loopvar_run.c
@@ -31,6 +31,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -88,7 +89,7 @@ run_driver(const char *driver, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) { runwait(rmcmd); return -1; }
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s build -o %s %s", driver, outbin, src);
diff --git a/test/wcc/949_missingpkg.c b/test/wcc/949_missingpkg.c
index 856ad436..a3edd782 100644
--- a/test/wcc/949_missingpkg.c
+++ b/test/wcc/949_missingpkg.c
@@ -53,7 +53,8 @@ run_miss(const char *bin)
 	snprintf(rmcmd, sizeof rmcmd, "rm -rf %s", tmpdir);
 	FILE *f = fopen(src, "w");
 	if (!f) { fprintf(stderr, "949 FAIL: stage miss\n"); runwait(rmcmd); return 1; }
-	fputs("import nosuchpkg;\n"
+	fputs("package main;\n"
+	    "import nosuchpkg;\n"
 	    "export fn main() i32 = { return 0; };\n", f);
 	fclose(f);
 
diff --git a/test/wcc/950_selfcheck.c b/test/wcc/950_selfcheck.c
index fef3cb52..300166fb 100644
--- a/test/wcc/950_selfcheck.c
+++ b/test/wcc/950_selfcheck.c
@@ -11,6 +11,7 @@
 #include <string.h>
 #include <unistd.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runcap(const char *cmd, char **outerr, size_t *outlen)
@@ -42,7 +43,7 @@ writefile(const char *path, const char *src)
 {
 	FILE *f = fopen(path, "wb");
 	if (!f) return -1;
-	fputs(src, f);
+	wwtest_fputs(src, f);
 	fclose(f);
 	return 0;
 }
diff --git a/test/wcc/978_intdiv_signed.c b/test/wcc/978_intdiv_signed.c
index 932748c8..75c52ae6 100644
--- a/test/wcc/978_intdiv_signed.c
+++ b/test/wcc/978_intdiv_signed.c
@@ -26,6 +26,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -383,7 +384,7 @@ run_driver(const char *driver, const struct row *r, int i)
 
 	FILE *f = fopen(src, "wb");
 	if (!f) { runwait(rmcmd); return -1; }
-	fputs(r->src, f);
+	wwtest_fputs(r->src, f);
 	fclose(f);
 
 	snprintf(cmd, sizeof cmd, "%s build -o %s %s",
diff --git a/test/wcc/989_barefn_collide_run.c b/test/wcc/989_barefn_collide_run.c
index 154fcfc4..d2b35fe6 100644
--- a/test/wcc/989_barefn_collide_run.c
+++ b/test/wcc/989_barefn_collide_run.c
@@ -12,27 +12,23 @@
  * class silent miscompile, gate-blind and symmetric cs==ww. Surfaced by
  * #80's `ww test` coexist (lib/test exports `run`).
  *
- * Fixture (the minimal real repro): a dir-package `aa` exporting `run`,
- * imported by a PACKAGE-LESS root that defines its OWN bare `fn run` and
- * calls it from `main`. Package-less is REQUIRED: a `package main` root's
- * decls mangle `main.<leaf>` (the package clause sets the module), so its
- * `run` would be `main.run` — no collision with `aa.run`, vacuous. Only a
- * package-less primary yields a truly BARE `run`, the #84 trigger.
+ * Strict-package (#24a) form: a dir-package `aa` exporting `run`, imported
+ * by a `package main;` root that defines its OWN `fn run` and calls it from
+ * `main`. The root's `run` mangles `main.run` — DISTINCT from the imported
+ * `aa.run` and from the bare entry `main`. The original #84 trigger (a
+ * truly BARE `run` from a PACKAGE-LESS root) is unreachable now that
+ * strict-package forbids package-less primaries; the #84 cgen machinery
+ * (mod_collect / mod_lookup_for_fn) stays dormant-but-load-bearing for
+ * genuinely package-less `//ww:module-reset` deps until #24b/#26.
  *
- * Asserts (combined `ww build`, BOTH driver stages; the fix lives in
- * mod_collect/mod_lookup_for_fn which run in every mode, so combined is
- * the minimal repro — `--sep` reproduces identically):
- *  1. Build + run, BOTH stages → exit 9 (the USER's bare `run`, return 9),
+ * Asserts (combined `ww build`, BOTH driver stages; `--sep` reproduces
+ * identically):
+ *  1. Build + run, BOTH stages → exit 9 (the user's `main.run`, return 9),
  *     never aa.run (return 5).
  *  2. cs==ww (rule 10): the combined `.s` is byte-identical between the
  *     two driver stages.
- *  3. NON-VACUITY + SOUNDNESS (the #84-specific signal): the `.s` has
- *     EXACTLY ONE `TEXT run` (the user's, bare) AND EXACTLY ONE `TEXT
- *     aa.run` (the import) — i.e. DISTINCT symbols, no dup. Pre-fix this
- *     row fails: two `TEXT aa.run` (the user's `run` mis-mangled onto the
- *     import) and zero bare `TEXT run`. (Exit alone is not a reliable
- *     signal: pre-fix the dup happened to bind the user's copy under this
- *     link order and still exited 9 — the label count is the proof.)
+ *  3. DISTINCTNESS: the `.s` has EXACTLY ONE `TEXT main.run` (the user's)
+ *     AND EXACTLY ONE `TEXT aa.run` (the import) — distinct symbols, no dup.
  *
  * Light wwstage-driver test (CLAUDE.md rule 14): all intermediates are
  * `-o`-redirected to /tmp, phase-parallel-safe. Models 989_sepbuild_run.c.
@@ -136,9 +132,13 @@ static const char *aa_src =
 	"package aa;\n"
 	"export fn run() i32 = { return 5; };\n";
 
-/* PACKAGE-LESS root (no `package` clause) → its `fn run` is bare (the #84
- * trigger); a `package main` root would mangle it `main.run` (vacuous). */
+/* Strict-package (#24a) root: declares `package main;`, so its `fn run`
+ * mangles `main.run` — DISTINCT from the imported `aa.run`, and from the
+ * bare entry `main`. The bare call `run()` resolves to the local `main.run`
+ * via the standard exact-hint path (the #84 special-case is bypassed for a
+ * moduled root). */
 static const char *root_src =
+	"package main;\n"
 	"import aa;\n"
 	"fn run() i32 = { return 9; };\n"
 	"export fn main() i32 = { return run(); };\n";
@@ -191,21 +191,20 @@ main(void)
 			fail++;
 			continue;
 		}
-		/* (1) the user's bare `run` (9) must win over imported aa.run (5). */
+		/* (1) the user's `main.run` (9) must win over imported aa.run (5). */
 		int rc = runwait(stg[s].prog);
 		if (rc != 9) {
 			fprintf(stderr, "84 FAIL: %s prog exit=%d expected 9 "
-			    "(bare user run, not aa.run=5)\n", stg[s].drv, rc);
+			    "(user main.run, not aa.run=5)\n", stg[s].drv, rc);
 			fail++;
 		}
-		/* (3) distinct symbols, no dup: exactly one bare `run` + one
-		 * `aa.run`. Pre-fix: two `aa.run` (user run mis-mangled) + zero
-		 * bare `run`. */
-		int nrun = count_text_label(stg[s].sfile, "run");
+		/* (3) distinct symbols, no dup: exactly one `main.run` + one
+		 * `aa.run`. */
+		int nrun = count_text_label(stg[s].sfile, "main.run");
 		int naa = count_text_label(stg[s].sfile, "aa.run");
 		if (nrun != 1 || naa != 1) {
-			fprintf(stderr, "84 FAIL: %s labels TEXT run=%d aa.run=%d "
-			    "(want 1/1 — bare user run distinct from import, no dup)\n",
+			fprintf(stderr, "84 FAIL: %s labels TEXT main.run=%d aa.run=%d "
+			    "(want 1/1 — user main.run distinct from import, no dup)\n",
 			    stg[s].drv, nrun, naa);
 			fail++;
 		}
@@ -224,8 +223,8 @@ out:
 		fprintf(stderr, "84: %d check(s) failed\n", fail);
 		return 1;
 	}
-	printf("barefn_collide: package-less root `fn run` (bare) coexists with "
-	    "imported aa.run — distinct labels, no dup, user run wins (exit 9), "
-	    "cs==ww, both driver stages (#84)\n");
+	printf("barefn_collide: `package main;` root `fn run` (main.run) coexists "
+	    "with imported aa.run — distinct labels, no dup, user run wins "
+	    "(exit 9), cs==ww, both driver stages (#84/#24a)\n");
 	return 0;
 }
diff --git a/test/wcc/989_septest_run.c b/test/wcc/989_septest_run.c
index 12eb1dcc..781fb768 100644
--- a/test/wcc/989_septest_run.c
+++ b/test/wcc/989_septest_run.c
@@ -41,6 +41,7 @@
 #include <sys/wait.h>
 #include <sys/stat.h>
 #include <dirent.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -114,7 +115,7 @@ write_file(const char *path, const char *body)
 {
 	FILE *f = fopen(path, "wb");
 	if (!f) return -1;
-	fputs(body, f);
+	wwtest_fputs(body, f);
 	fclose(f);
 	return 0;
 }
@@ -196,12 +197,13 @@ static struct tcase cases[] = {
 	/* a non-`fn() void` @test signature must loud-reject, not be coerced. */
 	{ "badsig", NULL, "test/wcc/data/attest_badsig.ww", 0, 0, 1 },
 	/* a user `fn run` COEXISTS with lib/test's bound runner (post-#80 synth
-	 * `use test;` keys the runner under "test", #84 mangles the user `run`
-	 * bare) → accept and run to exit 0. Under sep the two land in distinct
-	 * units (`run` in __root.s, `test.run` in test.s), so a regressed #84
-	 * collision re-mangles the user `run` to `test.run` and the force-loaded
-	 * root `.o` + test's `.a` both define `test.run` → w6l duplicate-symbol
-	 * → non-zero; exit 0 is the teeth (empirically confirmed). byteid=1 also
+	 * `use test;` keys the runner under "test"; under strict-package #24a the
+	 * user file's `package main;` mangles its `run` to `main.run`) → accept
+	 * and run to exit 0. Under sep the two land in distinct units (`main.run`
+	 * in __root.s, `test.run` in test.s), so a regressed collision re-mangles
+	 * the user `run` to `test.run` and the force-loaded root `.o` + test's
+	 * `.a` both define `test.run` → w6l duplicate-symbol → non-zero; exit 0
+	 * is the teeth (empirically confirmed). byteid=1 also
 	 * pins this coexist path's cs==ww per-pkg asm + synth presence — the
 	 * rule-10 leg the ported 997 `coexist_run` carried over the #84 mangle. */
 	{ "collide_run", NULL, "test/wcc/data/attest_userrun.ww", 0, 1, 0 },
diff --git a/test/wcc/990_selfhost.c b/test/wcc/990_selfhost.c
index 230f5767..24fcfb34 100644
--- a/test/wcc/990_selfhost.c
+++ b/test/wcc/990_selfhost.c
@@ -23,6 +23,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -472,7 +473,7 @@ probe_ww_compile(const char *bin)
 
 		FILE *f = fopen(src, "wb");
 		if (!f) { fail++; continue; }
-		fputs(progs[i].src, f);
+		wwtest_fputs(progs[i].src, f);
 		fclose(f);
 
 		snprintf(cmd, sizeof cmd, "timeout 180 %s/wwdump_ww -c %s > %s 2>/dev/null",
diff --git a/test/wcc/993_ww_ww.c b/test/wcc/993_ww_ww.c
index e8130bdb..99c45bd9 100644
--- a/test/wcc/993_ww_ww.c
+++ b/test/wcc/993_ww_ww.c
@@ -17,6 +17,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -129,7 +130,8 @@ run_exit_code(const char *bin, const char *driver, int code)
 	snprintf(src, sizeof src, "/tmp/ww_rc_%d_%d.ww", getpid(), code);
 	FILE *f = fopen(src, "w");
 	if (!f) return -1;
-	fprintf(f, "export fn main() i32 = {\n\treturn %d;\n};\n", code);
+	fprintf(f, "package main;\nexport fn main() i32 = {\n\treturn %d;\n};\n",
+	    code);
 	fclose(f);
 
 	char cmd[256];
@@ -151,7 +153,7 @@ run_build_fail(const char *bin, const char *driver)
 	snprintf(src, sizeof src, "/tmp/ww_badbuild_%d.ww", getpid());
 	FILE *f = fopen(src, "w");
 	if (!f) return -1;
-	fputs("export fn main() i32 = {\n\treturn 1\n", f);	/* no ; no } */
+	wwtest_fputs("export fn main() i32 = {\n\treturn 1\n", f);	/* no ; no } */
 	fclose(f);
 
 	char cmd[256];
@@ -178,7 +180,7 @@ run_missing_pkg(const char *bin, const char *driver)
 	snprintf(rmcmd,  sizeof rmcmd,  "rm -rf %s", tmpdir);
 	FILE *f = fopen(src, "w");
 	if (!f) { runwait(rmcmd); return 1; }
-	fputs("import nosuchpkg;\nexport fn main() i32 = { return 0; };\n", f);
+	wwtest_fputs("import nosuchpkg;\nexport fn main() i32 = { return 0; };\n", f);
 	fclose(f);
 
 	/* #8: the sep scratch is mkdir'd before the import-resolution failure,
@@ -225,7 +227,7 @@ main(void)
 	{
 		FILE *f = fopen(hello_src, "w");
 		if (!f) return 1;
-		fputs("import os;\n\n"
+		wwtest_fputs("import os;\n\n"
 		    "export fn main() i32 = {\n"
 		    "\tos.write(1, \"hi\\n\".ptr, 3u64);\n"
 		    "\treturn 0;\n"
diff --git a/test/wcc/994_w6c_ww.c b/test/wcc/994_w6c_ww.c
index 732bd5e5..268e8ddb 100644
--- a/test/wcc/994_w6c_ww.c
+++ b/test/wcc/994_w6c_ww.c
@@ -18,6 +18,7 @@
 #include <unistd.h>
 #include <sys/wait.h>
 #include <dirent.h>
+#include "wwtestpkg.h"
 
 static int
 runwait(const char *cmd)
@@ -101,7 +102,7 @@ write_file(const char *path, const char *content)
 {
 	FILE *f = fopen(path, "wb");
 	if (!f) return -1;
-	fputs(content, f);
+	wwtest_fputs(content, f);
 	fclose(f);
 	return 0;
 }
diff --git a/test/wcc/data/attest_userrun.ww b/test/wcc/data/attest_userrun.ww
index 16f96157..01845aa3 100644
--- a/test/wcc/data/attest_userrun.ww
+++ b/test/wcc/data/attest_userrun.ww
@@ -1,15 +1,16 @@
 // #80/#84 -T coexist — a user `fn run` COEXISTS with lib/test's bound
 // runner `run` (the synth main's callee). Once `ww test -c` bundles
 // lib/test, the synth `use test;` keys lib/test's `run` under module
-// "test" (#80: prepended before binding) and the user's package-less
-// `run` mangles to a DISTINCT bare `run` (#84) — no duplicate. Both
+// "test" (#80: prepended before binding) and the user's `package main;`
+// `run` mangles to a DISTINCT `main.run` (#84/#24a) — no duplicate. Both
 // stages accept under -T and the synth runner runs the @test to exit 0;
 // the user `run` must NOT hijack the entry. Pre-#80 this loud-rejected
 // "duplicate fn run". The gate (910/997 coexist_run) static-label-counts
-// the -T asm — exactly 1 `TEXT run` (user, bare) + 1 `TEXT test.run` (lib
+// the -T asm — exactly 1 `TEXT main.run` (user) + 1 `TEXT test.run` (lib
 // runner) — pinning #84 distinctness here in the REAL @test/-T path (a
-// dead-dup regression yields 0x run / 2x test.run). General callability of
-// the bare run is gated separately by 989_barefn_collide.
+// dead-dup regression yields 0x main.run / 2x test.run). General
+// callability of the user run is gated separately by 989_barefn_collide.
+package main;
 fn run() i32 = { return 9; };
 
 @test fn t_one() void = {
diff --git a/test/wcc/data/builtin_redecl_ok.ww b/test/wcc/data/builtin_redecl_ok.ww
index 38826204..c6b8a152 100644
--- a/test/wcc/data/builtin_redecl_ok.ww
+++ b/test/wcc/data/builtin_redecl_ok.ww
@@ -4,6 +4,7 @@
 // builtins into c.top, so installtop must DROP this redecl rather than
 // erroring. Both stages accept; the builtin `nomem` (= !void) wins, so
 // g()'s i32 arm returns 7. Pins the 771/774/926 shape.
+package main;
 type nomem = !void;
 fn g() (i32 | nomem) = { return 7; };
 export fn main() i32 = {
diff --git a/test/wcc/data/dup_def.ww b/test/wcc/data/dup_def.ww
index c7ab771b..ddf9d55d 100644
--- a/test/wcc/data/dup_def.ww
+++ b/test/wcc/data/dup_def.ww
@@ -1,5 +1,6 @@
 // #23 — two top-level defs of the same name in one (flat) module.
 // cstage's install pass rejects "duplicate def D"; wwstage now mirrors.
+package main;
 def D: i32 = 1;
 def D: i32 = 2;
 export fn main() i32 = { return 0; };
diff --git a/test/wcc/data/dup_fn.ww b/test/wcc/data/dup_fn.ww
index 2977f191..87422861 100644
--- a/test/wcc/data/dup_fn.ww
+++ b/test/wcc/data/dup_fn.ww
@@ -1,5 +1,6 @@
 // #23 — two top-level fns of the same name in the same (flat) module.
 // cstage's install pass rejects "duplicate fn foo"; wwstage now mirrors.
+package main;
 fn foo() i32 = { return 1; };
 fn foo() i32 = { return 2; };
 export fn main() i32 = { return foo(); };
diff --git a/test/wcc/data/dup_let.ww b/test/wcc/data/dup_let.ww
index a42a0530..298107bb 100644
--- a/test/wcc/data/dup_let.ww
+++ b/test/wcc/data/dup_let.ww
@@ -1,5 +1,6 @@
 // #23 — two top-level lets of the same name in one (flat) module.
 // cstage's install pass rejects "duplicate let g"; wwstage now mirrors.
+package main;
 let g: i32 = 1;
 let g: i32 = 2;
 export fn main() i32 = { return 0; };
diff --git a/test/wcc/data/dup_type.ww b/test/wcc/data/dup_type.ww
index 6bae68c0..dfe29df0 100644
--- a/test/wcc/data/dup_type.ww
+++ b/test/wcc/data/dup_type.ww
@@ -1,5 +1,6 @@
 // #23 — two top-level types of the same name in one (flat) module.
 // cstage's install pass rejects "duplicate type t"; wwstage now mirrors.
+package main;
 type t = i32;
 type t = u32;
 export fn main() i32 = { return 0; };
diff --git a/test/wcc/wwtestpkg.h b/test/wcc/wwtestpkg.h
new file mode 100644
index 00000000..edcaa4b0
--- /dev/null
+++ b/test/wcc/wwtestpkg.h
@@ -0,0 +1,61 @@
+/*
+ * wwtestpkg.h — strict-package (#24a) test support.
+ *
+ * Inline ww test fixtures historically omitted the `package main;` clause
+ * that the parser now requires (a missing clause is a hard error). These
+ * helpers inject it transparently so the fixtures stay terse, WITHOUT
+ * disturbing fixtures that already declare their own module identity.
+ *
+ * wwtest_fputs is a drop-in for fputs(src, f): it prepends `package main;`
+ * only when writing at the START of a fresh file (ftell == 0) AND the
+ * fixture does not already open with its own `package`/`//ww:module`
+ * directive. The ftell guard keeps multi-part writes and writes to
+ * non-seekable streams (stderr) behaving exactly like plain fputs.
+ */
+#ifndef WWTESTPKG_H
+#define WWTESTPKG_H
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+static inline int
+wwtest_has_module(const char *s)
+{
+	const char *p = s;
+	while (p != NULL) {
+		while (*p == ' ' || *p == '\t')
+			p++;
+		if (strncmp(p, "package ", 8) == 0
+		    || strncmp(p, "package\t", 8) == 0
+		    || strncmp(p, "//ww:module", 11) == 0)
+			return 1;
+		p = strchr(p, '\n');
+		if (p != NULL)
+			p++;
+	}
+	return 0;
+}
+
+static inline void
+wwtest_fputs(const char *src, FILE *f)
+{
+	if (ftell(f) == 0 && !wwtest_has_module(src))
+		fputs("package main;\n", f);
+	fputs(src, f);
+}
+
+/* In-process variant: a malloc'd copy of src with the clause prefixed
+ * (unless src declares its own module). Caller frees. */
+static inline char *
+wwtest_wrap(const char *src)
+{
+	const char *pfx = wwtest_has_module(src) ? "" : "package main;\n";
+	size_t np = strlen(pfx), ns = strlen(src);
+	char *b = malloc(np + ns + 1);
+	memcpy(b, pfx, np);
+	memcpy(b + np, src, ns + 1);
+	return b;
+}
+
+#endif