wcc+ww: //ww:module-reset boundary directive; package-less files keep module "" (#16 PREP-main)

Driver twins emit the line-comment directive only before package-less
files (peekpackage==nil); both lexers tokenize it (TK_MODRESET, appended
=87 so existing token values hold) and both parsers reset curmod — a
package-less file's decls get module "" instead of inheriting the last
bundled package (the sticky-curmod leak, task #11). Withdrawn
alternative: injecting 'package main' flips non-entry symbols
bare->main-prefixed (FFI-visible, broke 764). Codegen-neutral by proof:
bare symbols preserved, both stages emit byte-identical asm for a
directive-bearing combined. Transitional until strict-package rejects
package-less files outright. Includes 737 bad-deep pin for the
PREP-peek >2048 edge + 904/toktest rows for the new token.

cmd/wcc/lex.c

@@ -95,6 +95,23 @@ skipws(Lex *l)
 		}
 		if (c == '/' && lpeek(l, 1) == '/') {
 			lget(l); lget(l);	/* consume '//' */
+			/* #16 option-B: the driver emits `//ww:module-reset`
+			 * before a package-less file's bytes; recognize the
+			 * whole-line directive (without consuming differently)
+			 * and flag it so lexnext emits TK_MODRESET. The body is
+			 * then skipped like any comment. Mirrors the removed
+			 * `// MODULE:` lexer directive. */
+			{
+				static const char dir[] = "ww:module-reset";
+				size_t i = 0;
+				while (dir[i] && lpeek(l, i) == dir[i])
+					i++;
+				if (dir[i] == '\0') {
+					int nx = lpeek(l, i);
+					if (nx == '\n' || nx < 0)
+						l->modreset = 1;
+				}
+			}
 			while ((c = lpeek(l, 0)) >= 0 && c != '\n')
 				lget(l);
 			continue;
@@ -381,12 +398,15 @@ lexrune(Lex *l, Pos start)
 Tok
 lexnext(Lex *l)
 {
-	if (!skipws(l)) {
+	int more = skipws(l);
-		Pos p = lpos(l);
+	Pos start = lpos(l);
-		Tok t = (Tok){ TK_EOF, p, "", 0, {0}, TK_NONE };
+	/* A `//ww:module-reset` seen in the skipped run surfaces as its own
+	 * token before the next real one (#16 option-B boundary reset). */
+	if (l->modreset) { l->modreset = 0; EMIT(TK_MODRESET); }
+	if (!more) {
+		Tok t = (Tok){ TK_EOF, start, "", 0, {0}, TK_NONE };
 		return t;
 	}
-	Pos start = lpos(l);
 	int c = lpeek(l, 0);
 
 	if (isidstart(c))

cmd/wcc/parse.c

@@ -1363,6 +1363,19 @@ parsefile(Parser *p)
 			p->curmod = name;
 			continue;
 		}
+		/* `//ww:module-reset` — bundle boundary before a package-less
+		 * file. Reset curmod to NULL so the file's decls (and its own
+		 * `import os;`) are attributed to the primary module (""), not
+		 * the preceding bundled package. Codegen-neutral: NULL curmod
+		 * keeps bare symbols. (#16 option-B; closes task #11.)
+		 * Driver-emitted ONLY before package-less files; a hand-placed
+		 * directive after a mid-file `package` would strip subsequent
+		 * decls to bare — that usage is deliberate-only. */
+		if (p->cur.kind == TK_MODRESET) {
+			advance(p);
+			p->curmod = NULL;
+			continue;
+		}
 		Node *attrs = parseattrs(p);
 		int exp = accept(p, TK_EXPORT);
 		Node *d = NULL;

cmd/wcc/tok.c

@@ -103,6 +103,7 @@ tokname(Tkind k)
 	case TK_UNDER:		return "_";
 	case TK_ENUM:		return "enum";
 	case TK_MODULE:		return "package";
+	case TK_MODRESET:	return "//ww:module-reset";
 
 	case TK_LPAREN:		return "(";
 	case TK_RPAREN:		return ")";

cmd/wcc/ww.h

@@ -180,6 +180,10 @@ typedef enum {
 	TK_YIELD,	/* `yield expr;` — value-return from a match arm */
 	TK_ENUM,	/* Hare-style `enum [storage] { ... }` type form */
 	TK_MODULE,	/* `module foo;` — directory-as-module declaration */
+	TK_MODRESET,	/* `//ww:module-reset` — driver bundle boundary: reset
+			 * curmod to NULL before a package-less file's bytes
+			 * (#16 option-B; the package-less-entry attribution fix
+			 * that replaces the withdrawn `package main` inject). */
 
 	TK_LAST		/* sentinel for tables */
 } Tkind;
@@ -207,6 +211,9 @@ struct Lex {
 	i32	col;
 	Arena	*a;		/* token-text arena */
 	int	errs;
+	int	modreset;	/* a `//ww:module-reset` directive was seen in
+				 * the last skipped run; lexnext emits TK_MODRESET
+				 * before the next real token. */
 };
 
 void	lexinit(Lex*, Arena*, const char *file, const char *src, u64 len);

cmd/ww/main.c

@@ -306,6 +306,19 @@ expand(FILE *out, const char *path, struct ImportSet *visited,
 		else        expand(out, ipath, visited, libdir);
 	}
 
+	/* #16 option-B: a package-less file's decls would otherwise inherit
+	 * the preceding bundled module's sticky curmod (parser parse.c). Emit
+	 * a curmod-reset boundary directive so the lexer/parser attribute the
+	 * file to the primary module ("") — fixes the self-import false-fire
+	 * and the leaked-prefix bug, codegen-neutral (bare symbols kept; not
+	 * `package main`, which would main-prefix them). A packaged file's own
+	 * `package` decl already sets curmod, so it needs nothing — keeping
+	 * the directive out of every tracked combined.ww. (Task #11.) */
+	{
+		char pkg[128];
+		if (!peek_package(path, pkg, sizeof pkg))
+			fputs("//ww:module-reset\n", out);
+	}
 	rewind(in);
 	int ch;
 	while ((ch = fgetc(in)) != EOF) fputc(ch, out);

lib/ww/lex/lex.ww

@@ -56,6 +56,9 @@ type lex = struct {
 	line:   i32,
 	col:    i32,
 	errs:   i32,
+	// a `//ww:module-reset` directive was seen in the last skipped run;
+	// lexnext emits TK_MODRESET before the next real token (#16 opt-B).
+	modreset: i32,
 };
 
 export fn lexinit(l: *lex, file: str, src: *u8, len: u64) void = {
@@ -66,6 +69,7 @@ export fn lexinit(l: *lex, file: str, src: *u8, len: u64) void = {
 	l.line = 1;
 	l.col = 1;
 	l.errs = 0;
+	l.modreset = 0;
 };
 
 // srcb — byte at offset; helper that lifts the cast out of indexing.
@@ -127,6 +131,26 @@ fn skipws(l: *lex) bool = {
 			let c2: i32 = lpeek(l, 1u64);
 			if (c2 == '/') {
 				lget(l); lget(l);	// consume '//'
+				// #16 opt-B: recognize the driver's curmod-reset
+				// boundary directive `//ww:module-reset` (whole
+				// line) and flag it; lexnext emits TK_MODRESET.
+				// The body is then skipped like any comment.
+				// Mirrors cstage lex.c skipws. Compare via lpeek
+				// (no consume) so the skip loop below is unchanged.
+				let dir: str = "ww:module-reset";
+				let di: i32 = 0;
+				let matched: bool = true;
+				for (di < dir.len) {
+					if (lpeek(l, di: u64) != dir[di]: i32) {
+						matched = false; break;
+					};
+					di += 1;
+				};
+				if (matched) {
+					let nx: i32 = lpeek(l, dir.len: u64);
+					if (nx == '\n') { l.modreset = 1; }
+					else { if (nx < 0) { l.modreset = 1; }; };
+				};
 				for (true) {
 					let cx: i32 = lpeek(l, 0u64);
 					if (cx < 0) { return false; };
@@ -629,12 +653,19 @@ export fn lexnext(l: *lex, out: *tok) void = {
 	out.text = empty;
 	out.tsuffix = empty;
 
-	if (!skipws(l)) {
+	let more: bool = skipws(l);
-		let p: pos; curpos(l, &p);
+	let start: pos; curpos(l, &start);
-		emitsimple(&p, tkind.TK_EOF, out);
+	// A `//ww:module-reset` seen in the skipped run surfaces as its own
+	// token before the next real one (#16 opt-B boundary reset).
+	if (l.modreset != 0) {
+		l.modreset = 0;
+		emitsimple(&start, tkind.TK_MODRESET, out);
+		return;
+	};
+	if (!more) {
+		emitsimple(&start, tkind.TK_EOF, out);
 		return;
 	};
-	let start: pos; curpos(l, &start);
 	let c: i32 = lpeek(l, 0u64);
 
 	if (c >= 0) {

lib/ww/lex/tok.ww

@@ -118,7 +118,10 @@ type tkind = enum i32 {
 	TK_YIELD  = 84,
 	TK_ENUM   = 85,
 	TK_MODULE = 86,	// `module foo;` — directory-as-module decl
-	TK_LAST   = 87,
+	TK_MODRESET = 87,	// `//ww:module-reset` driver bundle boundary:
+				// reset curmod to "" before a package-less file
+				// (#16 option-B; cstage TK_MODRESET twin)
+	TK_LAST   = 88,
 };
 
 // ---- Pos / Tok --------------------------------------------------------
@@ -240,6 +243,7 @@ export fn tokname(k: tkind) str = {
 	case tkind.TK_UNDER:    return "_";
 	case tkind.TK_ENUM:     return "enum";
 	case tkind.TK_MODULE:   return "package";
+	case tkind.TK_MODRESET: return "//ww:module-reset";
 
 	case tkind.TK_LPAREN:   return "(";
 	case tkind.TK_RPAREN:   return ")";

lib/ww/lex/toktest.ww

@@ -128,11 +128,12 @@ fn checkname(k: tkind, want: str) void = {
 	signalled = 185; checkname(tkind.TK_ARROW, "->");
 	signalled = 186; checkname(tkind.TK_FATARROW, "=>");
 
-	signalled = 187; checkname(tkind.TK_LAST, "<last>");
+	signalled = 187; checkname(tkind.TK_MODRESET, "//ww:module-reset");
+	signalled = 188; checkname(tkind.TK_LAST, "<last>");
 
 	// Unknown kind → the post-switch fallback. TK_LAST is the highest
-	// named value (87); 88 is out of band, exercising the "<?>" tail.
+	// named value (88); 89 is out of band, exercising the "<?>" tail.
-	signalled = 188; checkname(88: tkind, "<?>");
+	signalled = 189; checkname(89: tkind, "<?>");
 };
 
 fn checkkw(s: str, want: tkind) void = {

lib/ww/parse/parse.ww

@@ -411,6 +411,22 @@ export fn parsefile(p: *parser) *node = {
 			p.curmod = name;
 			continue;
 		};
+		// `//ww:module-reset` — bundle boundary before a package-less
+		// file. Reset curmod to "" so the file's decls (and its own
+		// `import os;`) are attributed to the primary module, not the
+		// preceding bundled package. Codegen-neutral: "" curmod keeps
+		// bare symbols. (#16 option-B; closes task #11.)
+		// Driver-emitted ONLY before package-less files; a hand-placed
+		// directive after a mid-file `package` would strip subsequent
+		// decls to bare — that usage is deliberate-only.
+		if (p.curkind == tkind.TK_MODRESET) {
+			advance(p);
+			let empty: str;
+			empty.ptr = nil;
+			empty.len = 0;
+			p.curmod = empty;
+			continue;
+		};
 		let attrs = parseattrs(p);
 		let exported: i32 = 0;
 		if (p.curkind == tkind.TK_EXPORT) { exported = 1; advance(p); };

selfhost/cmd/w6c/main.combined.ww

@@ -6441,7 +6441,10 @@ type tkind = enum i32 {
 	TK_YIELD  = 84,
 	TK_ENUM   = 85,
 	TK_MODULE = 86,	// `module foo;` — directory-as-module decl
-	TK_LAST   = 87,
+	TK_MODRESET = 87,	// `//ww:module-reset` driver bundle boundary:
+				// reset curmod to "" before a package-less file
+				// (#16 option-B; cstage TK_MODRESET twin)
+	TK_LAST   = 88,
 };
 
 // ---- Pos / Tok --------------------------------------------------------
@@ -6563,6 +6566,7 @@ export fn tokname(k: tkind) str = {
 	case tkind.TK_UNDER:    return "_";
 	case tkind.TK_ENUM:     return "enum";
 	case tkind.TK_MODULE:   return "package";
+	case tkind.TK_MODRESET: return "//ww:module-reset";
 
 	case tkind.TK_LPAREN:   return "(";
 	case tkind.TK_RPAREN:   return ")";
@@ -6775,6 +6779,9 @@ type lex = struct {
 	line:   i32,
 	col:    i32,
 	errs:   i32,
+	// a `//ww:module-reset` directive was seen in the last skipped run;
+	// lexnext emits TK_MODRESET before the next real token (#16 opt-B).
+	modreset: i32,
 };
 
 export fn lexinit(l: *lex, file: str, src: *u8, len: u64) void = {
@@ -6785,6 +6792,7 @@ export fn lexinit(l: *lex, file: str, src: *u8, len: u64) void = {
 	l.line = 1;
 	l.col = 1;
 	l.errs = 0;
+	l.modreset = 0;
 };
 
 // srcb — byte at offset; helper that lifts the cast out of indexing.
@@ -6846,6 +6854,26 @@ fn skipws(l: *lex) bool = {
 			let c2: i32 = lpeek(l, 1u64);
 			if (c2 == '/') {
 				lget(l); lget(l);	// consume '//'
+				// #16 opt-B: recognize the driver's curmod-reset
+				// boundary directive `//ww:module-reset` (whole
+				// line) and flag it; lexnext emits TK_MODRESET.
+				// The body is then skipped like any comment.
+				// Mirrors cstage lex.c skipws. Compare via lpeek
+				// (no consume) so the skip loop below is unchanged.
+				let dir: str = "ww:module-reset";
+				let di: i32 = 0;
+				let matched: bool = true;
+				for (di < dir.len) {
+					if (lpeek(l, di: u64) != dir[di]: i32) {
+						matched = false; break;
+					};
+					di += 1;
+				};
+				if (matched) {
+					let nx: i32 = lpeek(l, dir.len: u64);
+					if (nx == '\n') { l.modreset = 1; }
+					else { if (nx < 0) { l.modreset = 1; }; };
+				};
 				for (true) {
 					let cx: i32 = lpeek(l, 0u64);
 					if (cx < 0) { return false; };
@@ -7348,12 +7376,19 @@ export fn lexnext(l: *lex, out: *tok) void = {
 	out.text = empty;
 	out.tsuffix = empty;
 
-	if (!skipws(l)) {
+	let more: bool = skipws(l);
-		let p: pos; curpos(l, &p);
+	let start: pos; curpos(l, &start);
-		emitsimple(&p, tkind.TK_EOF, out);
+	// A `//ww:module-reset` seen in the skipped run surfaces as its own
+	// token before the next real one (#16 opt-B boundary reset).
+	if (l.modreset != 0) {
+		l.modreset = 0;
+		emitsimple(&start, tkind.TK_MODRESET, out);
+		return;
+	};
+	if (!more) {
+		emitsimple(&start, tkind.TK_EOF, out);
 		return;
 	};
-	let start: pos; curpos(l, &start);
 	let c: i32 = lpeek(l, 0u64);
 
 	if (c >= 0) {
@@ -8913,6 +8948,22 @@ export fn parsefile(p: *parser) *node = {
 			p.curmod = name;
 			continue;
 		};
+		// `//ww:module-reset` — bundle boundary before a package-less
+		// file. Reset curmod to "" so the file's decls (and its own
+		// `import os;`) are attributed to the primary module, not the
+		// preceding bundled package. Codegen-neutral: "" curmod keeps
+		// bare symbols. (#16 option-B; closes task #11.)
+		// Driver-emitted ONLY before package-less files; a hand-placed
+		// directive after a mid-file `package` would strip subsequent
+		// decls to bare — that usage is deliberate-only.
+		if (p.curkind == tkind.TK_MODRESET) {
+			advance(p);
+			let empty: str;
+			empty.ptr = nil;
+			empty.len = 0;
+			p.curmod = empty;
+			continue;
+		};
 		let attrs = parseattrs(p);
 		let exported: i32 = 0;
 		if (p.curkind == tkind.TK_EXPORT) { exported = 1; advance(p); };

selfhost/cmd/ww/main.combined.ww

@@ -3315,6 +3315,19 @@ fn expand(c: *expctx, pathcs: *u8) void = {
 		i = j + 1u64;
 	};
 
+	// #16 option-B: a package-less file's decls would otherwise inherit
+	// the preceding bundled module's sticky curmod (parser parse.ww). Emit
+	// a curmod-reset boundary directive so the lexer/parser attribute the
+	// file to the primary module ("") — fixes the self-import false-fire
+	// and the leaked-prefix bug, codegen-neutral (bare symbols kept; not
+	// `package main`, which would main-prefix them). A packaged file's own
+	// `package` decl already sets curmod, so it needs nothing — keeping
+	// the directive out of every tracked combined.ww. (Task #11.)
+	if (peekpackage(pathcs) == nil) {
+		let d: str = "//ww:module-reset\n";
+		os.writeall(c.out, d.ptr, d.len: u64);
+	};
+
 	os.writeall(c.out, bufp, blen);
 	os.writeall(c.out, "\n".ptr, 1u64);
 };

selfhost/cmd/ww/main.ww

@@ -529,6 +529,19 @@ fn expand(c: *expctx, pathcs: *u8) void = {
 		i = j + 1u64;
 	};
 
+	// #16 option-B: a package-less file's decls would otherwise inherit
+	// the preceding bundled module's sticky curmod (parser parse.ww). Emit
+	// a curmod-reset boundary directive so the lexer/parser attribute the
+	// file to the primary module ("") — fixes the self-import false-fire
+	// and the leaked-prefix bug, codegen-neutral (bare symbols kept; not
+	// `package main`, which would main-prefix them). A packaged file's own
+	// `package` decl already sets curmod, so it needs nothing — keeping
+	// the directive out of every tracked combined.ww. (Task #11.)
+	if (peekpackage(pathcs) == nil) {
+		let d: str = "//ww:module-reset\n";
+		os.writeall(c.out, d.ptr, d.len: u64);
+	};
+
 	os.writeall(c.out, bufp, blen);
 	os.writeall(c.out, "\n".ptr, 1u64);
 };

selfhost/cmd/wwdump/main.combined.ww

@@ -6441,7 +6441,10 @@ type tkind = enum i32 {
 	TK_YIELD  = 84,
 	TK_ENUM   = 85,
 	TK_MODULE = 86,	// `module foo;` — directory-as-module decl
-	TK_LAST   = 87,
+	TK_MODRESET = 87,	// `//ww:module-reset` driver bundle boundary:
+				// reset curmod to "" before a package-less file
+				// (#16 option-B; cstage TK_MODRESET twin)
+	TK_LAST   = 88,
 };
 
 // ---- Pos / Tok --------------------------------------------------------
@@ -6563,6 +6566,7 @@ export fn tokname(k: tkind) str = {
 	case tkind.TK_UNDER:    return "_";
 	case tkind.TK_ENUM:     return "enum";
 	case tkind.TK_MODULE:   return "package";
+	case tkind.TK_MODRESET: return "//ww:module-reset";
 
 	case tkind.TK_LPAREN:   return "(";
 	case tkind.TK_RPAREN:   return ")";
@@ -6775,6 +6779,9 @@ type lex = struct {
 	line:   i32,
 	col:    i32,
 	errs:   i32,
+	// a `//ww:module-reset` directive was seen in the last skipped run;
+	// lexnext emits TK_MODRESET before the next real token (#16 opt-B).
+	modreset: i32,
 };
 
 export fn lexinit(l: *lex, file: str, src: *u8, len: u64) void = {
@@ -6785,6 +6792,7 @@ export fn lexinit(l: *lex, file: str, src: *u8, len: u64) void = {
 	l.line = 1;
 	l.col = 1;
 	l.errs = 0;
+	l.modreset = 0;
 };
 
 // srcb — byte at offset; helper that lifts the cast out of indexing.
@@ -6846,6 +6854,26 @@ fn skipws(l: *lex) bool = {
 			let c2: i32 = lpeek(l, 1u64);
 			if (c2 == '/') {
 				lget(l); lget(l);	// consume '//'
+				// #16 opt-B: recognize the driver's curmod-reset
+				// boundary directive `//ww:module-reset` (whole
+				// line) and flag it; lexnext emits TK_MODRESET.
+				// The body is then skipped like any comment.
+				// Mirrors cstage lex.c skipws. Compare via lpeek
+				// (no consume) so the skip loop below is unchanged.
+				let dir: str = "ww:module-reset";
+				let di: i32 = 0;
+				let matched: bool = true;
+				for (di < dir.len) {
+					if (lpeek(l, di: u64) != dir[di]: i32) {
+						matched = false; break;
+					};
+					di += 1;
+				};
+				if (matched) {
+					let nx: i32 = lpeek(l, dir.len: u64);
+					if (nx == '\n') { l.modreset = 1; }
+					else { if (nx < 0) { l.modreset = 1; }; };
+				};
 				for (true) {
 					let cx: i32 = lpeek(l, 0u64);
 					if (cx < 0) { return false; };
@@ -7348,12 +7376,19 @@ export fn lexnext(l: *lex, out: *tok) void = {
 	out.text = empty;
 	out.tsuffix = empty;
 
-	if (!skipws(l)) {
+	let more: bool = skipws(l);
-		let p: pos; curpos(l, &p);
+	let start: pos; curpos(l, &start);
-		emitsimple(&p, tkind.TK_EOF, out);
+	// A `//ww:module-reset` seen in the skipped run surfaces as its own
+	// token before the next real one (#16 opt-B boundary reset).
+	if (l.modreset != 0) {
+		l.modreset = 0;
+		emitsimple(&start, tkind.TK_MODRESET, out);
+		return;
+	};
+	if (!more) {
+		emitsimple(&start, tkind.TK_EOF, out);
 		return;
 	};
-	let start: pos; curpos(l, &start);
 	let c: i32 = lpeek(l, 0u64);
 
 	if (c >= 0) {
@@ -8913,6 +8948,22 @@ export fn parsefile(p: *parser) *node = {
 			p.curmod = name;
 			continue;
 		};
+		// `//ww:module-reset` — bundle boundary before a package-less
+		// file. Reset curmod to "" so the file's decls (and its own
+		// `import os;`) are attributed to the primary module, not the
+		// preceding bundled package. Codegen-neutral: "" curmod keeps
+		// bare symbols. (#16 option-B; closes task #11.)
+		// Driver-emitted ONLY before package-less files; a hand-placed
+		// directive after a mid-file `package` would strip subsequent
+		// decls to bare — that usage is deliberate-only.
+		if (p.curkind == tkind.TK_MODRESET) {
+			advance(p);
+			let empty: str;
+			empty.ptr = nil;
+			empty.len = 0;
+			p.curmod = empty;
+			continue;
+		};
 		let attrs = parseattrs(p);
 		let exported: i32 = 0;
 		if (p.curkind == tkind.TK_EXPORT) { exported = 1; advance(p); };

test/wcc/737_direnum.c

@@ -133,6 +133,46 @@ main(void)
 		}
 	}
 
+	/* bad-deep: same mismatch, but one file's `package` decl sits behind
+	 * a >2048-byte comment header. Pins the PREP-peek whole-file read
+	 * (#16): the old 2048-capped peek missed that decl, so the strict-
+	 * same-package check skipped the file and the mismatch went
+	 * undetected (build wrongly succeeded); the whole-file peek finds it
+	 * → "differs from". Both stages. (reviewer-batcha pin.) */
+	{
+		const char *src = "test/wcc/data/direnum/bad_deep_entry.ww";
+		snprintf(errp, sizeof errp, "/tmp/direnum_%d_baddeep.err", getpid());
+
+		char cmd[2048];
+		snprintf(cmd, sizeof cmd, "%s build %s 2>%s >/dev/null",
+		    ww, src, errp);
+		int rc = runwait(cmd);
+		total++;
+		if (rc == 0) {
+			fprintf(stderr, "737[bad-deep-cstage]: expected build failure, succeeded\n");
+			fail++;
+		} else if (!stderr_contains(errp, "differs from")) {
+			fprintf(stderr, "737[bad-deep-cstage]: stderr missing 'differs from'\n");
+			fail++;
+		}
+		unlink(errp);
+
+		if (access(ww_ww, X_OK) == 0) {
+			snprintf(cmd, sizeof cmd, "%s build %s 2>%s >/dev/null",
+			    ww_ww, src, errp);
+			rc = runwait(cmd);
+			total++;
+			if (rc == 0) {
+				fprintf(stderr, "737[bad-deep-wwstage]: expected build failure, succeeded\n");
+				fail++;
+			} else if (!stderr_contains(errp, "differs from")) {
+				fprintf(stderr, "737[bad-deep-wwstage]: stderr missing 'differs from'\n");
+				fail++;
+			}
+			unlink(errp);
+		}
+	}
+
 	if (fail) {
 		fprintf(stderr, "737_direnum: %d/%d fixtures failed\n", fail, total);
 		return 1;

test/wcc/data/direnum/bad_deep_entry.ww

@@ -0,0 +1,5 @@
+package main;
+
+import bad_deep_pkg;
+
+export fn main() i32 = { return 0; };

test/wcc/data/direnum/bad_deep_pkg/a.ww

@@ -0,0 +1,3 @@
+package alpha;
+
+fn aaa() i32 = { return 1; };

test/wcc/data/direnum/bad_deep_pkg/b.ww

@@ -0,0 +1,54 @@
+// b.ww — #16 PREP-main peek-edge pin (reviewer-batcha).
+// This file's `package beta;` decl sits behind a comment header
+// longer than 2048 bytes ON PURPOSE: the old wwstage peekpackage
+// capped its read at 2048 bytes and would MISS the package decl
+// (return nil), so the strict-same-package dir-enum check would
+// skip this file and the alpha/beta mismatch would go undetected
+// (build wrongly succeeds). The PREP-peek whole-file read finds
+// `package beta;`, so the mismatch fires 'differs from' and the
+// build fails — which is what 737's bad_deep family asserts on
+// both stages. Do not shorten this header below 2048 bytes.
+//
+// padding line to push the package decl past the 2048-byte peek window.
+// padding line to push the package decl past the 2048-byte peek window.
+// padding line to push the package decl past the 2048-byte peek window.
+// padding line to push the package decl past the 2048-byte peek window.
+// padding line to push the package decl past the 2048-byte peek window.
+// padding line to push the package decl past the 2048-byte peek window.
+// padding line to push the package decl past the 2048-byte peek window.
+// padding line to push the package decl past the 2048-byte peek window.
+// padding line to push the package decl past the 2048-byte peek window.
+// padding line to push the package decl past the 2048-byte peek window.
+// padding line to push the package decl past the 2048-byte peek window.
+// padding line to push the package decl past the 2048-byte peek window.
+// padding line to push the package decl past the 2048-byte peek window.
+// padding line to push the package decl past the 2048-byte peek window.
+// padding line to push the package decl past the 2048-byte peek window.
+// padding line to push the package decl past the 2048-byte peek window.
+// padding line to push the package decl past the 2048-byte peek window.
+// padding line to push the package decl past the 2048-byte peek window.
+// padding line to push the package decl past the 2048-byte peek window.
+// padding line to push the package decl past the 2048-byte peek window.
+// padding line to push the package decl past the 2048-byte peek window.
+// padding line to push the package decl past the 2048-byte peek window.
+// padding line to push the package decl past the 2048-byte peek window.
+// padding line to push the package decl past the 2048-byte peek window.
+// padding line to push the package decl past the 2048-byte peek window.
+// padding line to push the package decl past the 2048-byte peek window.
+// padding line to push the package decl past the 2048-byte peek window.
+// padding line to push the package decl past the 2048-byte peek window.
+// padding line to push the package decl past the 2048-byte peek window.
+// padding line to push the package decl past the 2048-byte peek window.
+// padding line to push the package decl past the 2048-byte peek window.
+// padding line to push the package decl past the 2048-byte peek window.
+// padding line to push the package decl past the 2048-byte peek window.
+// padding line to push the package decl past the 2048-byte peek window.
+// padding line to push the package decl past the 2048-byte peek window.
+// padding line to push the package decl past the 2048-byte peek window.
+// padding line to push the package decl past the 2048-byte peek window.
+// padding line to push the package decl past the 2048-byte peek window.
+// padding line to push the package decl past the 2048-byte peek window.
+// padding line to push the package decl past the 2048-byte peek window.
+package beta;
+
+fn bbb() i32 = { return 2; };