Catches the bot-generated-structurally-invalid-Go class that took
staging Platform(Go) red for hours on 2026-04-22 (PR #1769 commit
66ea0b64 nested a function declaration inside another function's body).
The patch tool applied it; the Go parser rejected it; every Go PR
targeting staging during the window failed CI through no fault of its
own.
Hook now runs `cd workspace-server && go build ./...` when any .go
file in workspace-server/ is staged. If the build fails, commit is
rejected with the first 20 lines of build output. Skip-with-warning
when go isn't installed (CI runners + bots without go bypass cleanly).
Cost: ~5-10s per commit that touches Go on a warm cache. Acceptable
for the class of bug it catches — the alternative (catch at PR-time
via CI) is too late, the malformed commit is already shared.
This is one of the three guards proposed in #1770. The other two
(branch-protection on `Platform (Go)` as required check; SHARED_RULES
clarification on bot-PR overrides) are admin / process changes that
need your action.
Closes the pre-commit half of #1770. Branch-protection + SHARED_RULES
work tracks separately.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2d1b15ecbc