Track B library test suite

• Type: feature
• Status: done
• Owner: Codex
• Opened: 2026-06-20
• Completed: 2026-06-20
• Relation: Track B testing workflow; companion to feature-parallel-tracks-stable-compiler, feature-platform-abstraction-layer, and the demo/library backlog.

Goal

Create a library-owned test path that is distinct from the compiler regression suite. Compiler tests remain the Track A self-host/fixedpoint gate; library tests run against $(PXX_STABLE) and can intentionally expose Track A or Track B work requests without destabilizing the compiler gate.

Delivered

• tools/library_suite.sh with three modes:
  • green - hard-fail curated library regressions.
  • discovery - non-gating probes that report GAP lines and Track A/B hints.
  • all - green plus discovery.
• Make targets (landed with the unit-search-path commit that touched the same Makefile block):
  • make library-suite-green
  • make library-suite-discovery
  • make library-suite
• Documentation in devdocs/developer/library-testing.md and devdocs/dev/parallel-tracks.md.
• Discovery probes for current known gaps:
  • chess -> missing Exception base class.
  • adventure -> missing text file IO (Assign etc.) on PAL.

Acceptance

• make library-suite-green passes against pinned stable.
• make library-suite exits 0 while reporting known discovery GAP lines.
• Discovery gaps point to progress tickets instead of living only in terminal output.

Log

• 2026-06-20 - Delivered in commit d142dc2 (test(lib): add Track B library suite). Verified make library-suite-green and make library-suite against pinned v18. This ticket was created after the fact because the suite was implemented before a progress ticket existed; keep future harness/library features ticketed before or during implementation.