Parallel tracks: pin libraries/demos to a "stable" compiler

• Type: feature
• Status: done
• Owner: —
• Opened: 2026-06-19
• Resolved: 2026-06-19

Goal

Let compiler work (track A) and library/demo work (track B) proceed in parallel without stepping on each other. The synchronisation boundary is a stable compiler binary: B compiles libraries and demo apps with a frozen, git-tracked pascal26 (stable_linux_amd64/default/latest) instead of the in-flux compiler/pascal26, so A can rebuild/regress the compiler freely while B keeps working against a known-good baseline. Current platform (x86-64) only; cross-compile is a later concern (assumed working on stable; the cross suites discover any gaps later).

Why now

The stabilize machinery already exists (make stabilize / check-stable / revert, versioned binaries under stable_linux_amd64/), but:

• the recorded stable is v8 (2026-05-29) — ~3 weeks and hundreds of procs behind HEAD; it cannot even compile the current examples, and
• nothing uses it: every lib/demo build runs against $(COMPILER), so library work is coupled to compiler churn.

Design

• Boundary = the stable binary. PXX_STABLE ?= stable_linux_amd64/default/latest. Track B targets compile with $(PXX_STABLE); an env override (PXX_STABLE=stable_linux_amd64/default/vN) pins a specific version when chasing a regression. B auto-follows latest by default.
• Publishing a new stable (track A, when a feature B needs lands): make stabilize runs the authoritative gate (make test + 4-iteration fixedpoint), bumps the version, and records the binary + sha + history.log line (timestamp, vN, sha, commit hash, commit subject). history.log is the changelog/sync point. Commit the new stable_linux_amd64/** artifacts.
• Lanes are soft guidelines, not walls. Ideal split: A owns compiler/** and compiler/cross/esp/bootstrap tests; B owns lib/**, examples/**, new test/lib_*, and the lib-test/demos Makefile block. But this is a dialect — A is free to touch libraries when a test or builtin needs it, and B may be asked to bug-hunt/advise. Grey zone is expected; the doc states the ideal, it does not enforce it.
• lib-test is NOT authoritative. The authoritative gate stays self-host compile + make test; features must not fail that. lib-test is a discovery / smoke harness for B. demos is a compile-smoke dashboard (exit 0, prints a per-app status table). When either surfaces missing/bugged library or language support, file a ticket — don't treat the red as a hard gate.

Deliverables

1. Refresh stable to current HEAD (make stabilize → v9). Unblocks B.
2. PXX_STABLE var + a staleness note in lib-test (recorded stable commit vs HEAD).
3. make lib-test — curated green subset against $(PXX_STABLE) (sudoku output check + lib/rtl smoke: collections, math). May hard-fail (smoke gate for B).
4. make demos — compile-smoke every examples/* app against $(PXX_STABLE); prints OK/FAIL table, exit 0 (dashboard, not a gate).
5. devdocs/dev/parallel-tracks.md — the A/B protocol.
6. File discovery tickets for the example breakages found while wiring this up (primes IntToStr, adventure Copy, chess parse error) — demonstrates the discovery→ticket loop.

Acceptance

make stabilize records a current-HEAD stable; make lib-test passes against it; make demos prints a status table; the protocol doc exists; make test and self-host fixedpoint stay green.

Log

• 2026-06-19 — opened and implementing immediately (user request to set up parallel compiler/library tracks).
• 2026-06-19 — done. PXX_STABLE var + pxx-stable-check / lib-test / demos targets landed; devdocs/dev/parallel-tracks.md written; stable refreshed v8 → v9 at current HEAD. lib-test green (sudoku exact + collections + math); demos dashboard runs. The dashboard immediately surfaced three real gaps, filed as discovery tickets: lib-intToStr-missing, lib-string-copy-trim-missing, bug-const-expr-shl-shr-not-folded. Resolved.