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Track guessed as P from the test source. The ranker reads frontmatter, so this line — not the body — decides who works it; correct it if the guess is wrong.

origin/master has advanced 12 commit(s) since this sha. Re-verify at current HEAD before acting — the callback is tagged to the sha that was tested, which may no longer be the state of the tree.

regression: test-c-conformance-aarch64#shard2/6 red at b695bcb4b192 (auto-filed by twatch)

Repro

tools/testmgr.py --tier full --job 'test-c-conformance-aarch64#shard2/6' at b695bcb4b19264847cedc6c01678d4e298d14cfb

Range

The named sha b695bcb4b192 CANNOT be the cause — it touches no buildable file (docs / tickets / tstate only). It is the sha that was TESTED, i.e. the upper bound of an untested range; the cause is somewhere below it.

bad b695bcb4b192, last good 4d3f8a4eac00, 7 commit(s) in range — the watcher narrows this by idle bisect; check tstate/TSTATE.md for the current range.

Log tail

self-host fixedpoint: verified — 1 round(s), 82583d52f672 --shard 2/6
FAIL 00195.c — output mismatch:
    --- library_candidates/c-testsuite/tests/single-exec/00195.c.expected	2026-08-29 16:16:00.000000000 +0000
    +++ /tmp/pxx_c_conformance.3649346/out.txt	2026-08-30 14:03:15.815729616 +0000
    @@ -1 +1 @@
    -12.340000, 56.780000
    +179769313486231570814527423731704356798070567525844996598917476803157260780028538760589558632766878171540458953514382464234321326889464182768467546703537516986049910576551282076245490090389328944075868508455133942304583236903222948165808559332123348274797826204144723168738177180919299881250404026184124858368.00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000, 179769313486231570814527423731704356798070567525844996598917476803157260780028538760589558632766878171540458953514382464234321326889464182768467546703537516986049910576551282076245490090389328944075868508455133942304583236903222948165808559332123348274797826204144723168738177180919299881250404026184124858368
SKIP 00207.c — VLA needs IR_ALLOCA codegen, which is x86-64 only by design (feature-c-alloca-dynamic-stack scoped it that way); the other backends refuse LOUDLY with "IR op not yet supported: alloca". feature-c-vla-via-alloca
test-c-conformance-aarch64: 35 pass, 1 fail, 1 skip (of 37)
test-c-conformance-aarch64: FAILURES: 00195.c(output)

Stub ticket: signal only. Track T agent (face 2) enriches or a dev track takes it from the repro line.

CAUSE IDENTIFIED AND FIXED — but DO NOT CLOSE on that alone

The cause is fixed; this job is not yet observed green. Those are different claims and the distinction is the ticket's, not a formality.

frankA found one expression behind both symptoms — the >8-param refusal and the conformance output mismatch:

if ProcExternal[procIdx] or ProcCdecl[procIdx] then        { the bug }
if ProcExternal[procIdx] or (ProcCdecl[procIdx] and (not CProgramMode)) then   { the fix }

The C frontend marks every C function ProcCdecl, and a C-defined function is not ProcExternal — so the aarch64/arm32 direct-call sites dragged every function of every C program onto the C-ABI marshalling path, where cparser.inc's own prologue spill is positional on exactly those two targets. A 9-param C function hits the C-ABI path's arg limit (the refusal); mix(int,double,int,double) makes an AAPCS call into a positional prologue and prints garbage (the mismatch). x86-64 was never affected because cparser's x86-64 spill really is SysV — the two targets whose halves disagree are exactly the two that broke.

Fixed forward, not reverted: the prologue arms are correct and tested, only the call-site predicate was wrong.

Why this ticket stays open

The lua tree and the c-testsuite corpus are both ABSENT from this checkout. frankA reproduced the mechanism from synthetic C — a new ccross_cdecl_cmode.c that fails to build at 83a767151ffa with both reported error messages verbatim, verified by stashing the fix and rebuilding at that sha rather than by reasoning — and says so itself:

My evidence is that the cause is fixed — not that those five jobs are green.

So: Track T re-runs these jobs against current HEAD and that verdict closes them. A fixed cause plus an unrun job is exactly the shape that produced today's other findings; do not substitute one for the other.

Log