examples/chess: PalBackendGetDents64 undefined (PAL backend not linked)

• Type: bug (library / PAL wiring — Track B)
• Status: backlog
• Owner: —
• Opened: 2026-06-21
• Relation: next examples/chess blocker after feature-local-typed-constant (done). Chess now parses past chess.pas:846.

Problem

Building chess with the stable compiler:

./compiler/pascal26 -Fulib/rtl -Fulib/pcl examples/chess/chess.pas /tmp/chess
pascal26:185: error: undefined variable (PalBackendGetDents64)

lib/rtl/platform.pas:185 calls PalBackendGetDents64, whose body lives in lib/rtl/platform/posix/platform_backend.pas (and an esp variant). The backend unit is not on chess's -Fu search path / not pulled by platform.pas, so the symbol resolves to nothing.

Direction (Track B)

• Ensure the posix platform_backend unit is reachable from platform.pas when chess is built (add the platform/posix dir to the search path, or have platform.pas uses the backend unit so it travels with the source).
• This is a library/search-path wiring issue, not a compiler feature gap — the compiler resolved every earlier chess construct.

Acceptance

• examples/chess advances past platform.pas:185 (hits the next gap, if any).

Resolved (v37)

examples/chess/chess.pas now compiles with the stable compiler — both with and WITHOUT -Fulib/rtl/platform/posix (the PalBackendGetDents64 symbol resolves; fixed upstream by the parser/backend wiring work that also unblocked the other units). It runs correctly: perft(1..4) = 20 / 400 / 8902 / 197281 (standard starting-position values). Acceptance met — chess advances well past platform.pas:185. Closing; the flagship oracle/benchmark scope stays in feature-demo-chess. Verified compiling + correct perft on pinned v37 (commit a89bb11).