Self-host M5: CI gate — sidecar SHA stamp must match spine entry before merge

[PurHur]

Category

bootstrap

Problem

prelinked/bootstrap-gen0/.m3_compiler_lib_sidecar.sha can drift from the SHA of test/selfhost/compiler_lib_spine_smoke/main.php while fast M5 gates still pass with a stale gen-0 blob. Workers editing the spine entry can merge without refreshing sidecars, causing cold-boot / vendor-absent failures that surface only under --strict or manual wave-check.

Goal

Add script/check-selfhost-spine-sidecar-sync.php and wire it into script/ci-fast.sh (inventory tail) so PR CI fails when the stamp ≠ spine entry SHA unless explicitly waived.

Repro (failure mode today)

# 1. Touch spine entry without updating sidecar stamp
echo '// drift probe' >> test/selfhost/compiler_lib_spine_smoke/main.php

# 2. Fast gates may still pass
make north-star5-verify-fast
php script/bootstrap-inventory.php --check

# 3. Stale blob only obvious when comparing SHAs manually
cat prelinked/bootstrap-gen0/.m3_compiler_lib_sidecar.sha
sha256sum test/selfhost/compiler_lib_spine_smoke/main.php

Expected after fix: step 2 exits non-zero with actionable message listing refresh commands.

php-src reference

N/A — project bootstrap integrity gate (#1492, docs/bootstrap-m5-fast-path.md).

Scope (this repo)

Piece	Path
New script	script/check-selfhost-spine-sidecar-sync.php
Stamp	prelinked/bootstrap-gen0/.m3_compiler_lib_sidecar.sha
Entry SSOT	test/selfhost/compiler_lib_spine_smoke/main.php
CI	script/ci-fast.sh inventory tail (after check-selfhost-spine-coverage-sync.php)
Docs	docs/bootstrap-m5-fast-path.md — refresh workflow
Unit test	test/unit/script/CheckSelfhostSpineSidecarSyncTest.php

Done when

• Sync script exits 0 on green master; non-zero when stamp ≠ sha256(main.php) (or documented canonical hash input)
• BOOTSTRAP_ALLOW_STALE_SIDECAR=1 opt-out documented for intentional blob batch PRs only
• ./script/ci-fast.sh invokes the check by default
• Unit test covers match, mismatch, and opt-out env
• Docs list: update stamp → optional make bootstrap-selfhost-lib-spine-smoke → refresh prelinked/bootstrap-gen0/

Verify

php script/check-selfhost-spine-sidecar-sync.php
make north-star5-verify-fast
php script/check-selfhost-spine-coverage-sync.php
./script/ci-fast.sh

Links

#1492 · #8703 · docs/bootstrap-m5-fast-path.md

[PurHur]

claim: worker-lane-c — starting this run

[PurHur]

Merged via #8807.

Verification

php script/check-selfhost-spine-sidecar-sync.php
# OK (stamp matches spine entry SHA-1 b51fd99816b92a6e303f855a69a4899d63988af9)

php vendor/bin/phpunit --filter CheckSelfhostSpineSidecarSyncTest
# OK (4 tests)

make bootstrap-selfhost-vm-driver-execute-probe
# OK

Drift repro: editing compiler_lib_spine_smoke/main.php without refreshing stamp now exits non-zero from check-selfhost-spine-sidecar-sync.php (waivable with BOOTSTRAP_ALLOW_STALE_SIDECAR=1). Gate wired into ci-fast.sh as SELFHOST_SPINE_SIDECAR_SYNC_GATE=1.

[PurHur]

claim: cursor-agent-lane-b — bootstrap fallback (sidecar stamp drift after #13793 StatsJitHelper spine entry; wave3 footnotes 3503→3504)

[PurHur]

Merged bootstrap fallback — #13808

Problem

After #13793 (StatsJitHelper.php spine entry), check-selfhost-spine-sidecar-sync failed (stamp 81dc45d2… ≠ spine c29a3e08…). Wave3 footnotes still showed 3503/3504 while spine is 3504/3504.

Fix

• Refresh prelinked/bootstrap-gen0/.m3_compiler_lib_sidecar.sha
• Regenerate docs/bootstrap-inventory.md (construct-flag drift)
• Sync spine footnotes 3503→3504 across README/roadmap/self-host docs + BootstrapSelfhostBundleTest

Verification

php script/check-selfhost-spine-sidecar-sync.php  # OK
php script/bootstrap-inventory.php --check        # OK 3504/3504
php script/check-wave3-roadmap-sync.php           # OK spine 3504/3504
make north-star5-verify-fast                      # OK

claim released: cursor-agent-lane-b — lane B parity queue empty; bootstrap gates green.