regression: test-c-conformance-arm32#shard5/6 red at 96b6bac331d9 (auto-filed by twatch)

• Type: regression (auto-filed by Track T watcher, host borg). Untriaged.
• Found: 2026-07-12T17:39:05Z
• Test source: tools/run_c_conformance.sh

Repro

tools/testmgr.py --tier full --job 'test-c-conformance-arm32#shard5/6' at 96b6bac331d9d8b9c838d0055a8e3841157314f1

Range

bad 96b6bac331d9, last good 96b6bac331d9, 0 commit(s) in range — the watcher narrows this by idle bisect; check tstate/TSTATE.md for the current range.

Log tail

FAIL 00204.c — output mismatch:
    --- library_candidates/c-testsuite/tests/single-exec/00204.c.expected	2026-07-07 21:11:07.000000000 +0200
    +++ /tmp/pxx_c_conformance.217834/out.txt	2026-07-12 19:37:04.289377047 +0200
    @@ -102,58 +102,58 @@
     0
     abcd
     abcd0000
    -abcd00000000
    -abcd000000000000
test-c-conformance-arm32: 35 pass, 1 fail, 0 skip (of 36)
test-c-conformance-arm32: FAILURES: 00204.c(output)

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

• 2026-07-12 — resolved, commit 38d8cb5e.

Triage: not a regression. bad == last good == 96b6bac331d9, 0 commits in range — this job was newly enrolled at eb63555d (cross-conformance matrix), so this is a first measurement of a pre-existing cross-target gap, not a break caused by a commit in range. The underlying bugs are tracked in their owning lanes: [[bug-c-generic-long-vs-int-on-32bit]] (00219), [[bug-c-lshift-promotion-aarch64]] (00200), [[bug-c-struct-byval-varargs-32bit]] (00204). The tests are still red; this stub is retired only because it duplicates those three.