In containers without unprivileged user namespaces every Codex command
fails, yet the review exits 0 and concludes 'no findings' (captured in
test/fixtures/codex-sandbox/). The validator now takes execution evidence:
'codex exec --json' command events and the 'codex review' stderr transcript
(a command that succeeded proves execution); sandbox failure lines on
stderr or in failed command output return unavailable(sandbox_unavailable);
exact 'could not run commands / read the diff' phrases are the last
fallback. Review text that merely discusses bwrap or namespaces still passes.
A free 'codex sandbox ... true' preflight (Linux, 10 s) runs before the paid
model probe and every automatic outside review; CODEX_MODE gains
sandbox_unavailable, and an inconclusive model probe reports unverified
instead of ready (exit code kept for stale callers). Every Codex site
(outside-voice resolver, /codex review, challenge, consult) takes its sandbox
from _GSTACK_CODEX_SANDBOX and pipes its result through the validator; a
static test parses rendered command positions for both. GSTACK_CODEX_NO_SANDBOX=1
(exactly 1, shell env only) switches to danger-full-access with a warning on
every use. Sandbox pins in existing tests move from the literal read-only to
the selected-sandbox variable; captured autoplan probes are judged against
the probe block they executed.
garrytan
0642559f60