PR iteration was bounded by single-job suite runs (~40-50 min critical
path) and by every first-of-ref build starting cold. Same suites, same
sanitizers, same gates — the schedule, the cache reuse, and a new
runtime coverage proof change.
- run-tests-parallel.sh accepts CBM_TEST_SHARD="i/N" and runs a
deterministic slice of --list-suites; unset selects everything, so the
path is inert outside CI. Known-heavy suites are dealt to shards in
weight order first (naive modulo stacked the two slowest, store_arch
and daemon_runtime, onto one job), the parallel wave and the serial
tail are sliced separately so every shard keeps its own quiet tail,
and the per-shard union guard proves each job ran exactly its slice.
- shard-completeness job: per-shard guards cannot see a mis-plumbed
CBM_TEST_SHARD (two jobs running the same slice passes every local
check while a slice runs nowhere). Every leg now uploads a manifest
(leg, i/N, sha of the full suite list, its slice) and one aggregation
job re-proves per leg that the shards agreed on the list, indices are
exactly 1..N, and the union of slices IS the list. Runs on unsharded
topologies too, where each leg's single manifest must cover the list.
- workflow topology (shard_suites input, off by default = byte-identical
to the pre-shard matrix): ubuntu legs run 3 shards, Windows 2 (every
extra Windows shard re-pays ~5 min of MSYS2 setup), macOS stays at 1
(not the critical path; mac runner concurrency ceilings are the
tightest). The Windows test job also pre-creates build\c with a
protected DACL so build products inherit it — workspace drive roots
grant Authenticated Users Modify by inheritance, which the activation
transaction's source-directory policy correctly refuses.
- ccache: a final ref-less restore key lets a fresh PR start from the
newest cache GitHub's scoping permits, and a nightly build-only
cache-warm workflow keeps main-scoped caches at most a day stale —
without it the fallback had no warm source, since nothing built in
main's scope. The strictly-per-ref policy this replaces cost ~8-12
minutes on every first-of-ref build for no safety gain:
CCACHE_COMPILERCHECK=content makes a stale or foreign cache able to
miss but never to return wrong output. Sharded legs restore-all/
save-one (every shard builds the identical objects, so shard 1's
cache carries the full set) — save volume stays flat and warm caches
stop being evicted by per-shard duplicates.
- suite timeouts: daemon_runtime joins the slow tier. It measures ~610s
solo on arm64 under ASan (10-round loop, no hang), so the 900s default
under a loaded 4-job CI runner was a slowness kill masquerading as a
hang detector.
Validated locally: 3-shard union over the real suite list is complete
with no duplicates, one top-heavy suite per shard, and the summed
3-shard totals reproduce the unsharded run exactly (6776 passed,
0 failed, 4 skipped).
Signed-off-by: Martin Vogel <martin.vogel.tech@gmail.com>
dependabot[bot]