ci: Reduce unnecessary builds and compiler-cache pressure

[paulgessinger]

Merge-group runs currently build Detray and Traccc even for unrelated changes, while SHA-keyed main compiler caches accumulate full snapshots against the shared 10 GB budget. This change reduces unnecessary builds and cache pressure, and speeds up the unused-file check.

[paulgessinger]

Additional information:

Changes

• Add merge-group changes jobs for Detray and Traccc using the existing path-filter pattern. Conservative filters include shared build inputs and Traccc's ACTS dependencies; existing PR/push filtering and job names are preserved.
• Retain the newest non-empty main compiler-cache archive per build variant and cache format after trusted main workflows complete. Recheck the replacement before deleting older archive IDs. PR and dependency caches are excluded; manual runs default to dry-run.
• Pass CCACHE_MAXSIZE into Linux wheel containers so their existing 500 MB limit takes effect instead of the 5 GB container default. Increase the Ubuntu FPE build's local cache from 500 MB to 1 GB after observing repeated cleanups during compilation.
• Use direct quiet grep in the unused-file checker to stop after the first match and avoid shell invocation and unnecessary output collection. Add regression checks to the CI self-tests.

Validation

• 12 Python regression tests passed, covering retention boundaries, replacement disappearance, API failures, wheel environment propagation, and unused-file matching/error handling.
• 28 path-filter cases and 14 gate status/cancellation cases passed.
• Actionlint passed with the existing optional Traccc compiler-matrix diagnostic excluded; zizmor 1.29.0, Black, Bash syntax, and whitespace checks passed.
• Full GNU/Linux unused-file benchmark: 206.880 s before, 40.484 s after (5.11x faster), with identical diagnostics and successful exit status.
• Live read-only cache dry run selected eight superseded archives totalling 3,588,771,767 bytes. No caches were deleted during development.

The retention workflow becomes active on main. It reduces storage pressure but does not impose an aggregate hard cap or prevent temporary pressure while new archives upload. End-to-end GitHub workflow validation is pending.

[github-actions]

📊: Physics performance monitoring for 5383248

Full contents

physmon summary

• ✅ Particles fatras
• ✅ Particles geant4
• ✅ Particles ttbar
• ✅ Vertices ttbar
• ✅ Truth tracking (KF)
• ✅ Truth tracking (GSF)
• ✅ Truth tracking (GX2F)
• ✅ Truth tracking (KF refit)
• ✅ Truth tracking (GSF refit)
• ✅ CKF finding performance | trackfinding | single muon | truth smeared seeding
• ✅ CKF fitting performance | trackfinding | single muon | truth smeared seeding
• ✅ CKF track summary | trackfinding | single muon | truth smeared seeding
• ✅ Seeding trackfinding | single muon | truth estimated seeding
• ✅ CKF finding performance | trackfinding | single muon | truth estimated seeding
• ✅ CKF fitting performance | trackfinding | single muon | truth estimated seeding
• ✅ CKF track summary | trackfinding | single muon | truth estimated seeding
• ✅ Seeding trackfinding | single muon | default seeding
• ✅ CKF finding performance | trackfinding | single muon | default seeding
• ✅ CKF fitting performance | trackfinding | single muon | default seeding
• ✅ CKF track summary | trackfinding | single muon | default seeding
• ✅ Seeding trackfinding | single muon | orthogonal seeding
• ✅ CKF finding performance | trackfinding | single muon | orthogonal seeding
• ✅ CKF fitting performance | trackfinding | single muon | orthogonal seeding
• ✅ CKF track summary | trackfinding | single muon | orthogonal seeding
• ✅ Seeding trackfinding | 4 muon x 50 vertices | default seeding
• ✅ CKF finding performance | trackfinding | 4 muon x 50 vertices | default seeding
• ✅ CKF fitting performance | trackfinding | 4 muon x 50 vertices | default seeding
• ✅ CKF track summary | trackfinding | 4 muon x 50 vertices | default seeding
• ✅ Ambisolver finding performance | trackfinding | 4 muon x 50 vertices | default seeding
• ✅ IVF notime | trackfinding | 4 muon x 50 vertices | default seeding
• ✅ AMVF gauss notime | trackfinding | 4 muon x 50 vertices | default seeding
• ✅ AMVF grid time | trackfinding | 4 muon x 50 vertices | default seeding
• ✅ Seeding trackfinding | ttbar with 200 pileup | default seeding
• ✅ CKF finding performance | trackfinding | ttbar with 200 pileup | default seeding
• ✅ CKF fitting performance | trackfinding | ttbar with 200 pileup | default seeding
• ✅ CKF track summary | trackfinding | ttbar with 200 pileup | default seeding
• ✅ Ambisolver finding performance | trackfinding | ttbar with 200 pileup | default seeding
• ✅ ML Ambisolver | trackfinding | ttbar with 200 pileup | default seeding
• ✅ AMVF gauss notime | trackfinding | ttbar with 200 pileup | default seeding
• ✅ AMVF grid time | trackfinding | ttbar with 200 pileup | default seeding
• 🔵️ Comparison - Truth tracking (GX2F vs KF)

[github-actions]

Public API surface diff

No change to the public API surface. ✅

Invalidated by push of 5383248

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
1 Accepted issue

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud