fred
10a1f82031
ci/woodpecker/pr/ci Pipeline was canceled
Review finding from scooby: this PR added a failure branch the harness structurally could not reach. The fake tmux answered `has-session` only for `=_holder:0.0`, so every non-holder agent landed in the session-is-gone branch no matter what — the `elif` (tmux still reports the session, no pane PID after the retries) had zero coverage and no way to get any. That is the same shape as the bug this PR exists to fix, one layer down: a code path shipped green where the gate that should measure it cannot. Less severe, because the branch fails closed at exit 69 rather than reporting success — but "the harness can't reach it" is the sentence that precedes the next silent regression, so it gets closed here rather than filed. `MOSAIC_TEST_HELD_SESSIONS` lets a case name targets the shim should also answer for. It answers them only AFTER `new-session`, and that detail is the whole trick: the launcher asks `has-session` about the same name twice — once at line 255 where a yes means "already running, exit 0", and once at 417 where a yes means "the session survived". A shim answering yes to both short-circuits at the first and never reaches the branch under test. It would have looked like coverage while measuring the idempotency path. Both failure modes were measured, not reasoned about: - toggle absent (the old shim): `code=pane-did-not-survive` — the case lands on the wrong branch, which is exactly the unreachability being reported. - toggle answering unconditionally: launcher exits 0 via the idempotency short-circuit — "launcher reported success over a session with no resolvable pane PID". - toggle gated on new-session: `code=pane-pid-unresolved`, exit 69. The case also asserts the diagnostic is not `pane-did-not-survive` and does not mention the heartbeat, so the two pane faults cannot collapse into one message. Gates: bash -n · launcher harness rc=0 · test-fleet-units.sh (real tmux) rc=0 · fleet specs 342 passed. Refs #1241.