The test passed on the author's macOS but exited 1 on CI: with
--skip-build the build lock is never acquired (the probe asserted a
release that never happened), and the unmocked platform launch fixups
ran against the fake empty executable — on Linux,
_packaged_desktop_launch_command's sandbox helper is missing and sudo
is unavailable, so cmd_gui exits 1 before the handoff.
- Run the real acquire path (no --skip-build) so the lock is genuinely
held, then probe its release at the Electron handoff.
- Pin HERMES_HOME to tmp so the checkout-keyed lock path is isolated
from the runner's home.
- Stub _desktop_linux_sandbox_fixup and _installed_desktop_launch_target:
environment-dependent platform fixups are not this test's subject.
5c66b2e02f