[krishhgg]

What this fixes

A flaky test failed the macOS 27 job on #85 (run 38186117753, commit d328730):

RecoveryScriptTests.swift:4026: XCTAssertEqual failed: ("3") is not equal to ("2")
RecoveryScriptTests.swift:4027: XCTAssertEqual failed: ("2") is not equal to ("1")
calls: ["sudo -n .../bin/pmset -a disablesleep 0", "sudo SIGHUP", "sudo SIGTERM", "sudo SIGHUP", "sudo SIGTERM", "sudo SIGTERM"]

testTheSupervisorOutlivesItsRunAndGroupSignalsAndHoldsTheLockUntilItReapsTheCommand sends the backstop's process group one SIGTERM and one SIGHUP. It expects the fake sudo to log each once. The fake logged both twice. The backstop was fine. The bug is in the test's fake.

Why the fake logged twice

The fake's wait loop ran $(date +%s) on every pass. Bash 3.2 starts a command substitution (the $(...) child shell) with the parent's pending traps and trap commands. The child runs pending traps before its first command. So a signal that arrives after the loop's own trap check, and before that fork, runs the trap in the child and again in the parent.

The change

• The watchdog deadline uses bash's SECONDS counter, so the wait loop forks nothing but /bin/sleep.
• The deadline is set before the fake publishes its pid. A test may signal the group as soon as the pid appears, and there is no longer a date for that signal to kill.
• No assertion changed. Only the fake's text and its doc comment.

This is the same fix as #34's e52ea07 and b96f62a, copied from #34's head, so #34 merges cleanly over it.

Evidence

Local, M5 MacBook Pro, macOS 26.2 (25C56), at bb5cf2b plus this diff (the diff's hash matched before and after the runs):

Run	Result
swift build --build-tests	ok
The failing test alone, 5 times	5 of 5 passed
All of RecoveryScriptTests	231 tests, 0 failures

The same test also failed on this Mac in its other form, on #86's branch, which doesn't have this fix. The fake ended itself after 26 s with command.ended = watchdog, though its watchdog is 60 s. The group's SIGTERM had killed the date in deadline=$(( $(date +%s) + 60 )), so the deadline was 60 seconds after 1970. The Mac did not sleep during that run (pmset -g log). This change sets the deadline before the pid appears, with no date, so that form is gone too.

Codex (gpt-6.1-sol, xhigh, read-only) found nothing at f71900f. It reproduced the CI log's HUP, TERM, HUP, TERM, TERM pattern with a standalone bash 3.2 script, and found no other test fake with a logging trap and a command substitution in its wait loop.

CI on this PR runs main's workflow, so it tests on macOS 26 only. #85 adds the macOS 27 job.

Tests-only PR: no Mac report needed.

🤖 Generated with Claude Code

Confidence Score: 5/5

The PR appears safe to merge.

Summary

Changes the fake sudo watchdog to use Bash’s SECONDS instead of running date.

• The fake sudo watchdog uses SECONDS while it waits.

No actionable issues found. Tests were not run during this review.

_{Reviews (1) · Last reviewed commit: "Tests: let the fake sudo wait on SECONDS..." · Reviewed by Greptile}