Root cause already diagnosed — see [[bug-c-plain-char-lost-its-type-identity-not-just-its-signedness]]. One commit (
07414aa89) turned plaincharinto an 8-bit integer rather than a signed character type. Do not triage this stub separately; it goes green when that ticket does. origin/master has advanced 3 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#shard2/6 red at ff1a30aae401 (auto-filed by twatch)
- Type: regression (auto-filed by Track T watcher, host xeon). Untriaged.
- Found: 2026-08-03T11:09:51Z
- Test source: tools/run_c_conformance.sh
Repro
tools/testmgr.py --tier full --job 'test-c-conformance#shard2/6' at ff1a30aae4014fa8b6d4b235f5667c2760035e68
Range
bad ff1a30aae401, last good unknown, 0 commit(s) in range — the watcher narrows this
by idle bisect; check tstate/TSTATE.md for the current range.
Log tail
SKIP 00207.c — VLA (int a[n], runtime bound) — refused loudly since the silent-zero sizing corrupted the frame; feature-c-vla-via-alloca
FAIL 00219.c — compile error:
pascal26:2805: error: _Generic: no matching association and no default
near: >>> printf
test-c-conformance: 35 pass, 1 fail, 1 skip (of 37)
test-c-conformance: FAILURES: 00219.c(compile)
Stub ticket: signal only. Track T agent (face 2) enriches or a dev track takes it from the repro line.
Triage (Track T, 2026-08-04) — closed by its root cause
The stub said it goes green when
[[bug-c-plain-char-lost-its-type-identity-not-just-its-signedness]] does, and
that ticket resolved in 0816af23f. Verified from the watcher's published
state rather than by re-running here (this checkout has no c-testsuite
corpus, so the job would SKIP and a skip is not evidence):
pass test-c-conformance#shard2/6
pass test-c-conformance-aarch64#shard2/6
pass test-c-conformance-arm32#shard2/6
pass test-c-conformance-i386#shard2/6
pass test-c-conformance-riscv32#shard2/6
xeon's job map currently holds zero non-passing entries, so the four cross
variants are green too — the _Generic failure on 00219.c was one root cause
across all five, exactly as the stub predicted.
No separate fix was needed and none is filed: this stub existed only to carry the signal until the owning lane landed the real one.
- 2026-08-04 — resolved, commit 4c0ea6707.