test: re-point 990/994/#110 off combined.ww-input to sep-feed (M4 E4-keystone, #22)

The E3 driver flip makes build_one_sep the sole path; it writes
.sepwork/*.unit.ww, not <stem>.combined.ww, so the flip stops producing
combined.ww. Migrate its consumers to sep-feed first, while both build
paths still exist (reversible; all 5 stage binaries stay byte-identical):

- 990_selfhost: resolveunit drives `ww build --sep` and reads
  <stem>.sepwork/__root.unit.ww; probe_cgen_match gains err.ww (sep
  inlines fmt's .wwi only, so cs==ww holds); probe_ww_links re-expressed
  as `ww_ww build --sep`->run; probe_bootstrap_fixed_point removed (the
  monolith path it tested is deleted by E4 -- the self-application axis
  lives in `make bootstrap`, the cs==ww axis in 995).
- 994_w6c_ww: drop the combined-fed emit_eq + corpus; keep the live
  per-package cs-sep==ww-sep oracle (cmp_sepwork + diff_one + bad[]).
- #110 combined_ww_fresh gate removed (its regen-vs-committed premise
  dies with its producer).

Non-vacuity proven: a one-line emitter mutation reddens 994's per-package
cs!=ww check across 15 packages; revert restores green.

test/run

@@ -187,25 +187,6 @@ if [ "${UNIT:-0}" != "1" ]; then
 	done | xargs -0 -n2 -P "$JOBS" "$0" --one || true
 	p2par_end=$(date +%s.%N)
 	fi
-
-	# combined.ww freshness gate (#110): 990/995 above unconditionally
-	# regenerate every tracked combined.ww amalgamation, so a diff vs HEAD
-	# here means an embedded source changed without its derived artifact
-	# being regenerated + committed (the #28 staleness hole the per-file
-	# byte-id gates were blind to). git ls-files keeps new combined.ww
-	# auto-covered (rule-13 SSoT). Lives inside the UNIT guard because
-	# test-unit skips 990/995 and thus the regen.
-	name=combined_ww_fresh
-	if git diff --exit-code -- $(git ls-files '*.combined.ww') > /dev/null 2>&1; then
-		printf 'ok   %s\n' "$name" > "$RESULTS/$name.status"
-	else
-		{
-			printf 'FAIL %s (stale; regen + commit the derived amalgamation)\n' "$name"
-			echo '--- stale combined.ww ---'
-			git diff --name-only -- $(git ls-files '*.combined.ww')
-		} > "$RESULTS/$name.status"
-		: > "$RESULTS/$name.fail"
-	fi
 fi
 
 fail=0

test/wcc/990_selfhost.c

@@ -518,21 +518,21 @@ cleanup:
 }
 
 /* resolveunit — produce <fixture>'s RESOLVED translation unit the way
- * the driver does. `ww build` concatenates the module with its
+ * the sep driver does. `ww build --sep` composes the root package's
- * transitive imports into <stem>.combined.ww (cmd/ww/main.c expand()),
+ * <stem>.sepwork/__root.unit.ww: the transitive deps' `.wwi` interface
- * which is the single unit w6c/wwdump actually consume; w6c never
+ * stubs followed by the root package body — the single self-contained
- * resolves imports itself (cmd/w6c/main.c reads one pre-concatenated
+ * unit w6c/wwdump consume for the root (the producer compiles it with no
- * file). Feeding a raw module file therefore leaves its import refs
+ * -I; cmd/ww/main.c sep_compose_unit). Feeding a raw module file instead
- * (os.write, fmt.errorln, strconv.i64tos …) unresolved — a partial
+ * would leave its import refs (os.write, fmt.errorln, strconv.i64tos …)
- * unit harec's module::resolve never hands the checker, and which the
+ * unresolved — a partial unit harec's module::resolve never hands the
- * ww-stage asserttyped invariant (check.ww) is not meant to see.
+ * checker, and which the ww-stage asserttyped invariant must not see.
  *
- * Built in a private /tmp dir (a copy of the fixture) so no .combined.ww
+ * Built in a private /tmp dir (a copy of the fixture) so the sepwork
- * / .s / .o lands next to the repo source. The link step fails for an
+ * lands off the repo source tree. The link step fails for an import-only
- * import-only module (no main), but .combined.ww is written before
+ * module (no main), but the unit is written before the link, so we detect
- * codegen, so we detect that artifact rather than gating on the build
+ * that artifact rather than gating on the build exit. Writes the owning
- * exit. Writes the owning tmpdir into `td` (caller rm -rf's it) and the
+ * tmpdir into `td` (caller rm -rf's it) and the unit path into `out`.
- * combined path into `out`. Returns 0 on success, -1 otherwise. */
+ * Returns 0 on success, -1 otherwise. */
 static int
 resolveunit(const char *bin, const char *cwd, const char *fixture,
     int idx, char *td, size_t tdsz, char *out, size_t outsz)
@@ -549,18 +549,19 @@ resolveunit(const char *bin, const char *cwd, const char *fixture,
 	snprintf(cmd, sizeof cmd, "cp %s/%s %s", cwd, fixture, tmpsrc);
 	runwait(cmd);
 	snprintf(cmd, sizeof cmd,
-	    "cd %s && timeout 180 %s/ww build %s >/dev/null 2>&1", td, bin, base);
+	    "cd %s && timeout 180 %s/ww build --sep %s >/dev/null 2>&1",
+	    td, bin, base);
 	runwait(cmd);
-	snprintf(out, outsz, "%s", tmpsrc);
+	char stem[768];
-	char *dot = strrchr(out, '.');
+	snprintf(stem, sizeof stem, "%s", tmpsrc);
+	char *dot = strrchr(stem, '.');
 	if (dot && strcmp(dot, ".ww") == 0) *dot = '\0';
-	size_t n = strlen(out);
+	snprintf(out, outsz, "%s.sepwork/__root.unit.ww", stem);
-	snprintf(out + n, outsz - n, ".combined.ww");
 	return access(out, 0) == 0 ? 0 : -1;
 }
 
 /* Probe 4: ww-side checker (wwdump_ww -r) runs name resolution on each
- * selfhost fixture's RESOLVED unit (imports concatenated — see
+ * selfhost fixture's RESOLVED unit (sep root unit — see
  * resolveunit) and reports zero unresolved. The raw file would leave
  * its `import` refs (os/fmt/strconv/ascii members) unresolved, i.e. the
  * partial unit the asserttyped invariant must never see (harec resolves
@@ -578,9 +579,9 @@ probe_resolve(const char *bin)
 	};
 	int fail = 0;
 	for (int i = 0; fixtures[i]; i++) {
-		char td[64], combined[1024], a[256], cmd[2048];
+		char td[64], unit[1024], a[256], cmd[2048];
 		if (resolveunit(bin, cwd, fixtures[i], i, td, sizeof td,
-		    combined, sizeof combined) != 0) {
+		    unit, sizeof unit) != 0) {
 			fprintf(stderr, "resolve FAIL: %s — no resolved unit\n",
 			    fixtures[i]);
 			fail++;
@@ -588,7 +589,7 @@ probe_resolve(const char *bin)
 		}
 		snprintf(a, sizeof a, "/tmp/wwd_r_%d", getpid());
 		snprintf(cmd, sizeof cmd, "timeout 180 %s/wwdump_ww -r %s > %s 2>/dev/null",
-		    bin, combined, a);
+		    bin, unit, a);
 		int rc = runwait(cmd);
 		if (rc != 0) {
 			fprintf(stderr, "resolve FAIL: %s exited %d (unresolved names)\n",
@@ -657,72 +658,21 @@ probe_dump_stable(const char *bin)
 	return fail ? -1 : 0;
 }
 
-/* Probe 9: full bootstrap fixed-point. ww1 → ww2 → ww3 with
+/* Probe 7: end-to-end via the ww driver's sep path. `ww_ww build --sep`
- * cmp ww2.s == ww3.s and cmp ww2 == ww3 (byte-identical binaries).
+ * drives the ww-side toolchain (w6c_ww → w6a_ww → w6l_ww) over the
- * This is the textbook self-host gate: the compiler must reach a
+ * fixture's package graph — per-package compile, archive, reverse-topo
- * fixed point under iterated self-compilation. */
+ * link — and we run the result, comparing the exit code to the fixture's
-static int
+ * declared expectation. This is the bootstrap-grade signal: it doesn't
-probe_bootstrap_fixed_point(const char *bin)
+ * require byte-identity, only that the ww toolchain links the fixture's
-{
+ * dep stack (sym/typ/ast via the syntax package, in a SEPARATE `.o`) into
-	char cwd[1024];
+ * a functionally correct binary. The single-`.s` link the combined path
-	if (getcwd(cwd, sizeof cwd) == NULL) return -1;
+ * used is gone with combined-mode (the syntax symbols live in their own
-	char tmpdir[64];
+ * `.o` under --sep, not in the root unit). */
-	snprintf(tmpdir, sizeof tmpdir, "/tmp/wwfp_%d", getpid());
-	mkdir(tmpdir, 0755);
-	char ww2s[512], ww2o[512], ww2e[512];
-	char ww3s[512], ww3o[512], ww3e[512];
-	char rt[1024], cmd[4096];
-	snprintf(rt,   sizeof rt,   "%s/../lib/libwwrt.a", bin);
-	snprintf(ww2s, sizeof ww2s, "%s/ww2.s",  tmpdir);
-	snprintf(ww2o, sizeof ww2o, "%s/ww2.o",  tmpdir);
-	snprintf(ww2e, sizeof ww2e, "%s/ww2",    tmpdir);
-	snprintf(ww3s, sizeof ww3s, "%s/ww3.s",  tmpdir);
-	snprintf(ww3o, sizeof ww3o, "%s/ww3.o",  tmpdir);
-	snprintf(ww3e, sizeof ww3e, "%s/ww3",    tmpdir);
-	int fail = 0;
-	/* ww1 -> ww2 */
-	snprintf(cmd, sizeof cmd,
-	    "timeout 180 %s/wwdump_ww -c %s/selfhost/cmd/wwdump/main.combined.ww > %s 2>/dev/null",
-	    bin, cwd, ww2s);
-	if (runwait(cmd) != 0) { fprintf(stderr, "fp FAIL: ww1 self-compile\n"); fail++; goto cleanup; }
-	snprintf(cmd, sizeof cmd, "timeout 180 %s/w6a -o %s %s 2>/dev/null", bin, ww2o, ww2s);
-	if (runwait(cmd) != 0) { fprintf(stderr, "fp FAIL: w6a ww2.s\n"); fail++; goto cleanup; }
-	snprintf(cmd, sizeof cmd, "timeout 180 %s/w6l -o %s %s %s 2>/dev/null", bin, ww2e, ww2o, rt);
-	if (runwait(cmd) != 0) { fprintf(stderr, "fp FAIL: w6l ww2\n"); fail++; goto cleanup; }
-	/* ww2 -> ww3 */
-	snprintf(cmd, sizeof cmd,
-	    "timeout 180 %s -c %s/selfhost/cmd/wwdump/main.combined.ww > %s 2>/dev/null",
-	    ww2e, cwd, ww3s);
-	if (runwait(cmd) != 0) { fprintf(stderr, "fp FAIL: ww2 self-compile\n"); fail++; goto cleanup; }
-	snprintf(cmd, sizeof cmd, "timeout 180 %s/w6a -o %s %s 2>/dev/null", bin, ww3o, ww3s);
-	if (runwait(cmd) != 0) { fprintf(stderr, "fp FAIL: w6a ww3.s\n"); fail++; goto cleanup; }
-	snprintf(cmd, sizeof cmd, "timeout 180 %s/w6l -o %s %s %s 2>/dev/null", bin, ww3e, ww3o, rt);
-	if (runwait(cmd) != 0) { fprintf(stderr, "fp FAIL: w6l ww3\n"); fail++; goto cleanup; }
-	/* The fixed-point check: ww2.s == ww3.s, ww2 == ww3. */
-	snprintf(cmd, sizeof cmd, "cmp -s %s %s", ww2s, ww3s);
-	if (runwait(cmd) != 0) { fprintf(stderr, "fp FAIL: ww2.s != ww3.s (no fixed point)\n"); fail++; }
-	snprintf(cmd, sizeof cmd, "cmp -s %s %s", ww2e, ww3e);
-	if (runwait(cmd) != 0) { fprintf(stderr, "fp FAIL: ww2 != ww3 binaries\n"); fail++; }
-cleanup:
-	snprintf(cmd, sizeof cmd, "rm -rf %s", tmpdir);
-	runwait(cmd);
-	return fail ? -1 : 0;
-}
-
-/* Probe 7: end-to-end via wwdump_ww. Use `ww build` to produce the
- * concatenated source as a side effect, then drive ww-cgen → w6a →
- * w6l → run, comparing the binary's exit code to the fixture's
- * declared expectation. This is the bootstrap-grade signal: it
- * doesn't require ww-cgen output to be byte-identical to C-cgen,
- * only to be functionally correct. The byte-match probe above is
- * useful while it lasts but layout choices (slot allocation order,
- * spill placement) eventually diverge between cgens; correctness is
- * the test that scales. */
 static int
 probe_ww_links(const char *bin)
 {
 	const char *fixtures[][2] = {
-		{ "selfhost/test/sym_link.ww", "42" },	/* sym/typ/ast/mem */
+		{ "selfhost/test/sym_link.ww", "42" },	/* sym/typ/ast via syntax */
 		{ NULL, NULL },
 	};
 	char cwd[1024];
@@ -745,41 +695,18 @@ probe_ww_links(const char *bin)
 		char cmd[4096];
 		snprintf(cmd, sizeof cmd, "cp %s/%s %s", cwd, fix, tmpsrc);
 		runwait(cmd);
-		/* ww build to get the .combined.ww as a side effect. */
+		/* Isolated WW_PKGCACHE: the default out/.pkgcache is shared with
-		snprintf(cmd, sizeof cmd,
+		 * the other phase-2 gates' sep builds (perturb + race). -o + the
-		    "cd %s && timeout 180 %s/ww build -I %s/lib/ww -I %s/selfhost/cmd/wcc %s >/dev/null 2>&1",
+		 * absolute src/-I paths route every side file into tmpdir, so no
-		    tmpdir, bin, cwd, cwd, tmpsrc);
+		 * cwd dependency. */
-		if (runwait(cmd) != 0) {
+		char wexep[512];
-			fprintf(stderr, "ww-links FAIL: ww build %s\n", fix);
-			fail++;
-			goto cleanup;
-		}
-		/* Now compile the combined source via the ww frontend. */
-		char combinedp[512], wsp[512], wop[512], wexep[512];
-		snprintf(combinedp, sizeof combinedp, "%s.combined.ww", stem);
-		snprintf(wsp, sizeof wsp, "%s_w.s", stem);
-		snprintf(wop, sizeof wop, "%s_w.o", stem);
 		snprintf(wexep, sizeof wexep, "%s_w", stem);
 		snprintf(cmd, sizeof cmd,
-		    "timeout 180 %s/wwdump_ww -c %s > %s 2>/dev/null", bin, combinedp, wsp);
+		    "WW_PKGCACHE='%s.cache' timeout 180 %s/ww_ww build --sep "
+		    "-o %s -I %s/lib/ww -I %s/selfhost/cmd/wcc %s >/dev/null 2>&1",
+		    stem, bin, wexep, cwd, cwd, tmpsrc);
 		if (runwait(cmd) != 0) {
-			fprintf(stderr, "ww-links FAIL: wwdump_ww -c %s\n", fix);
+			fprintf(stderr, "ww-links FAIL: ww_ww build --sep %s\n", fix);
-			fail++;
-			goto cleanup;
-		}
-		snprintf(cmd, sizeof cmd, "timeout 180 %s/w6a -o %s %s 2>/dev/null",
-		    bin, wop, wsp);
-		if (runwait(cmd) != 0) {
-			fprintf(stderr, "ww-links FAIL: w6a %s\n", fix);
-			fail++;
-			goto cleanup;
-		}
-		char rt[1024];
-		snprintf(rt, sizeof rt, "%s/../lib/libwwrt.a", bin);
-		snprintf(cmd, sizeof cmd, "timeout 180 %s/w6l -o %s %s %s 2>/dev/null",
-		    bin, wexep, wop, rt);
-		if (runwait(cmd) != 0) {
-			fprintf(stderr, "ww-links FAIL: w6l %s\n", fix);
 			fail++;
 			goto cleanup;
 		}
@@ -791,8 +718,6 @@ probe_ww_links(const char *bin)
 			fail++;
 		}
 cleanup:
-		/* Sweep tmpdir contents, then remove. ww build also drops a
-		 * C-built binary at <stem> — clean it too. */
 		snprintf(cmd, sizeof cmd, "rm -rf %s", tmpdir);
 		runwait(cmd);
 	}
@@ -800,23 +725,20 @@ cleanup:
 }
 
 /* Probe 6: ww-cgen byte-matches C-cgen on each selfhost fixture's
- * RESOLVED unit (imports concatenated — see resolveunit). The driver
+ * RESOLVED unit (sep root unit — see resolveunit). The producer feeds
- * always feeds w6c/wwdump a concatenated unit, so the byte-identity
+ * w6c/wwdump that self-contained unit, so the byte-identity gate (rule
- * gate (rule 10) belongs on that shape rather than the raw file; the
+ * 10) belongs on that shape rather than the raw file.
- * unit also drags in the imported stdlib (os/strconv/ascii), widening
- * the convergence set. When this stays empty the cmp ww2 ww3 ceiling
- * becomes feasible.
  *
- * selfhost/cmd/wcc/err.ww is exercised by probe_resolve but not here:
+ * err.ww is included now (it was excluded under combined-mode, where its
- * its resolved unit pulls in lib/fmt, whose `formattable` match the
+ * unit inlined lib/fmt's BODY and the ww checker rejected fmt's
- * ww-stage checker rejects (check.ww casecovers/casevariantin raise
+ * `formattable` match-exhaustiveness): the sep unit inlines only fmt's
- * ck.errs, so wwdump -c bails before cgen) — a cs≠ww match-exhaustive-
+ * `.wwi` INTERFACE, so the fmt body never reaches the checker and err's
- * ness divergence, latent for the bootstrap (the compiler's own
+ * root cgen converges cs==ww. */
- * main.combined.ww imports no fmt) and tracked separately. */
 static int
 probe_cgen_match(const char *bin)
 {
 	const char *files[] = {
+		"selfhost/cmd/wcc/err.ww",
 		"lib/ww/syntax/tok.ww",
 		"selfhost/test/smoke.ww",
 		NULL,
@@ -825,9 +747,9 @@ probe_cgen_match(const char *bin)
 	if (getcwd(cwd, sizeof cwd) == NULL) return -1;
 	int fail = 0;
 	for (int i = 0; files[i]; i++) {
-		char td[64], combined[1024], a[256], b[256], cmd[2048];
+		char td[64], unit[1024], a[256], b[256], cmd[2048];
 		if (resolveunit(bin, cwd, files[i], i, td, sizeof td,
-		    combined, sizeof combined) != 0) {
+		    unit, sizeof unit) != 0) {
 			fprintf(stderr, "cgen-match FAIL: %s — no resolved unit\n",
 			    files[i]);
 			fail++;
@@ -836,10 +758,10 @@ probe_cgen_match(const char *bin)
 		snprintf(a, sizeof a, "/tmp/wwd_cm_%d_c", getpid());
 		snprintf(b, sizeof b, "/tmp/wwd_cm_%d_w", getpid());
 		snprintf(cmd, sizeof cmd, "timeout 180 %s/w6c %s > %s 2>/dev/null",
-		    bin, combined, a);
+		    bin, unit, a);
 		runwait(cmd);
 		snprintf(cmd, sizeof cmd, "timeout 180 %s/wwdump_ww -c %s > %s 2>/dev/null",
-		    bin, combined, b);
+		    bin, unit, b);
 		runwait(cmd);
 		char *bc = NULL, *bw = NULL;
 		size_t nc = 0, nw = 0;
@@ -876,19 +798,26 @@ main(void)
 	if (probe_ww_compile(bin)  != 0) fail++;
 	if (probe_cgen_match(bin)  != 0) fail++;
 	if (probe_ww_links(bin)    != 0) fail++;
-	if (probe_bootstrap_fixed_point(bin) != 0) fail++;
 
 	if (fail) {
 		fprintf(stderr, "selfhost: %d probe(s) failed\n", fail);
 		return 1;
 	}
+	/* The ww1->ww2->ww3 binary fixed point is no longer reproducible here:
+	 * it self-compiled wwdump as a monolith from main.combined.ww, a model
+	 * combined-mode provided and --sep retires (the sep root unit holds only
+	 * the root body + dep INTERFACE stubs, not a linkable whole program). The
+	 * two axes it covered now live elsewhere: the self-application fixed point
+	 * (iterated self-compile converges, ww2==ww3==ww4) is `make bootstrap`'s
+	 * sep-path gate (migrated E2-C1); the orthogonal wwstage==cstage byte
+	 * identity is 995_self_rebuild, which drives ww_ww --sep over all five
+	 * tools (wwdump included) and byte-compares against the cstage binaries. */
 	printf("selfhost: codegen ok; smoke=42; wwdump stable; "
 	    "ww lexer matches C on 8 fixtures (-t); "
 	    "ww parser matches C on 32 fixtures (-a); "
-	    "ww checker resolves 3 fixtures' import-concatenated units (-r); "
+	    "ww checker resolves 3 fixtures' sep root units (-r); "
 	    "ww cgen compiles + runs 13 ww programs (incl. compound -= regression); "
-	    "ww cgen byte-matches C on 2 resolved units (tok/smoke); "
+	    "ww cgen byte-matches C on 3 sep root units (err/tok/smoke); "
-	    "ww cgen builds runnable binaries from sym/typ/ast/mem stack; "
+	    "ww toolchain sep-builds + runs the syntax dep stack (sym_link=42)\n");
-	    "ww1 -> ww2 -> ww3 fixed-point reached: ww2.s == ww3.s, ww2 == ww3 byte-identical\n");
 	return 0;
 }

test/wcc/994_w6c_ww.c

@@ -120,41 +120,6 @@ files_eq(const char *a, const char *b)
 	return eq ? 0 : 1;
 }
 
-/* Tier-C oracle helper (rob-c6-spec §2 / amendment-B): a sep-built w6c at
- * `sepw6c` must EMIT byte-identical asm to the combined-built `w6c_ww` on
- * `target`. (We assert OUTPUT equivalence, never `cmp` the tool binaries —
- * sep vs combined differ by a constant link-layout delta.) Returns 0 on
- * byte-identical .s, non-zero otherwise. */
-static int
-emit_eq(const char *sepw6c, const char *w6c_ww, const char *target,
-    const char *label)
-{
-	char a[64], b[64], cmd[4096];
-	snprintf(a, sizeof a, "/tmp/wwc6tc_%d_sep.s", getpid());
-	snprintf(b, sizeof b, "/tmp/wwc6tc_%d_comb.s", getpid());
-	snprintf(cmd, sizeof cmd, "timeout 240 %s -o %s %s 2>/dev/null",
-	    sepw6c, a, target);
-	if (runwait(cmd) != 0) {
-		fprintf(stderr, "Tier-C FAIL: sep-w6c emit errored on %s\n", label);
-		unlink(a);
-		return 1;
-	}
-	snprintf(cmd, sizeof cmd, "timeout 240 %s -o %s %s 2>/dev/null",
-	    w6c_ww, b, target);
-	if (runwait(cmd) != 0) {
-		fprintf(stderr, "Tier-C FAIL: combined-w6c_ww emit errored on %s\n",
-		    label);
-		unlink(a); unlink(b);
-		return 1;
-	}
-	int rc = files_eq(a, b);
-	if (rc != 0)
-		fprintf(stderr, "Tier-C FAIL: %s — sep-out != combined-out "
-		    "(M4 output-equivalence broken)\n", label);
-	unlink(a); unlink(b);
-	return rc == 0 ? 0 : 1;
-}
-
 /* cs==ww over a sep-build's per-package artifacts: every .s/.o/.wwi the
  * cstage driver produced in `csdir` must be byte-identical to the wwstage
  * driver's same-named file in `wwdir` (rule 10; the .wwi interface files
@@ -309,17 +274,6 @@ main(void)
 		{ NULL, NULL },
 	};
 
-	/* Source-tree corpus: the same .combined.ww files the bootstrap
-	 * fixed point chews on. Confirms w6c_ww handles realistic inputs,
-	 * not just hand-tailored ones. */
-	const char *combined_rel[] = {
-		"selfhost/cmd/wwdump/main.combined.ww",
-		"selfhost/cmd/w6a/main.combined.ww",
-		"selfhost/cmd/w6l/main.combined.ww",
-		"selfhost/cmd/ww/main.combined.ww",
-		NULL,
-	};
-
 	int fail = 0, n = 0;
 
 	for (int i = 0; progs[i].label; i++) {
@@ -330,12 +284,6 @@ main(void)
 		unlink(src);
 		n++;
 	}
-	for (int i = 0; combined_rel[i]; i++) {
-		char p[2048];
-		snprintf(p, sizeof p, "%s/%s", cwd, combined_rel[i]);
-		if (diff_one(bin, combined_rel[i], p) != 0) fail++;
-		n++;
-	}
 
 	/* #50: the check pass is wired into both wwdump_ww -c and
 	 * w6c_ww in front of cgen. Pre-#50, a hard type error parsed
@@ -376,22 +324,19 @@ main(void)
 		n++;
 	}
 
-	/* ---- Tier-C capstone (#46 c6, rob-c6-spec §2 / amendment-B) ----------
+	/* ---- Tier-C capstone (#46 c6, rob-c6-spec §2 / amendment-B; M4 #89) ---
-	 * Fold the dual-path soak into this bootstrap oracle: a w6c built by
+	 * The load-bearing M4 oracle: build w6c by SEPARATE compilation under
-	 * SEPARATE compilation must EMIT byte-identical .s to the combined-built
+	 * BOTH driver stages and prove they sep-produce byte-identical per-package
-	 * w6c_ww on every real bootstrap input, and both driver stages must
+	 * .s/.o/.wwi (cs==ww on the real tool's sep artifacts, rule 10). The
-	 * sep-produce byte-identical per-package .s/.o/.wwi (cs==ww on the real
+	 * combined corpus + the sep-out==combined-out leg are gone — combined-mode
-	 * tool's sep artifacts). This is the load-bearing M4 proof — the
+	 * is being retired (E3 flip), so combined.ww is no longer fed as compiler
-	 * combined-out==sep-out leg the bootstrap fixed point alone cannot reach.
+	 * INPUT; the per-pkg cs==ww comparison is the surviving live oracle. COLD
-	 * We assert OBSERVABLE OUTPUT, never `cmp` the tool binaries (sep vs
+	 * (pid-keyed scratch, wiped); heavy (≈ one bootstrap leg) → phase-2. */
-	 * combined differ by a constant link-layout delta). COLD (pid-keyed
-	 * scratch, wiped); heavy (≈ one bootstrap leg) → this gate is phase-2. */
 	{
 		char inc[4096], cmd[16384];
 		snprintf(inc, sizeof inc,
 		    "-I %s/lib -I %s/lib/ww -I %s/selfhost/cmd/wcc", cwd, cwd, cwd);
-		char w6c_ww[2048], root[2048];
+		char root[2048];
-		snprintf(w6c_ww, sizeof w6c_ww, "%s/w6c_ww", bin);
 		snprintf(root, sizeof root, "%s/selfhost/cmd/w6c/main.ww", cwd);
 
 		struct { const char *drv, *tag; char prog[2048]; int ok; }
@@ -415,29 +360,6 @@ main(void)
 			n++;
 		}
 
-		/* OUTPUT equivalence on every real bootstrap input: each built
-		 * sep-w6c vs the combined w6c_ww (the M4 combined-out==sep-out bar;
-		 * cs==ww follows since both sep stages match the same reference). */
-		const char *targ[] = {
-			"selfhost/cmd/w6c/main.combined.ww",
-			"selfhost/cmd/wwdump/main.combined.ww",
-			"selfhost/cmd/w6a/main.combined.ww",
-			"selfhost/cmd/w6l/main.combined.ww",
-			"selfhost/cmd/ww/main.combined.ww",
-			NULL,
-		};
-		for (int s = 0; s < 2; s++) {
-			if (!stg[s].ok) continue;
-			for (int i = 0; targ[i]; i++) {
-				char t[2048], label[256];
-				snprintf(t, sizeof t, "%s/%s", cwd, targ[i]);
-				snprintf(label, sizeof label, "sep-%s emit %s",
-				    stg[s].tag, targ[i]);
-				if (emit_eq(stg[s].prog, w6c_ww, t, label) != 0) fail++;
-				n++;
-			}
-		}
-
 		/* cs==ww on the real tool's sep .s/.o/.wwi (rule 10). */
 		if (stg[0].ok && stg[1].ok) {
 			char csdir[2176], wwdir[2176];
@@ -458,9 +380,8 @@ main(void)
 		fprintf(stderr, "w6c_ww: %d/%d diff(s) failed\n", fail, n);
 		return 1;
 	}
-	printf("w6c_ww: byte-identical to wwdump_ww -c on %d corpus inputs "
+	printf("w6c_ww: byte-identical to wwdump_ww -c on %d in-source corpus "
-	    "(in-source + selfhost combined.ww) + Tier-C: sep-built w6c emits "
+	    "inputs + Tier-C: cs==ww sep .s/.o/.wwi on the real w6c build\n",
-	    "== combined w6c_ww on all bootstrap inputs, cs==ww sep .s/.o/.wwi\n",
 	    n);
 	return 0;
 }