expandRemotePath() returns an already-quoted shell fragment
("$HOME"'/path'), but three call sites wrapped its output in shq()
again: the withRemoteUpdateMutex python argv, the reservation/lock/
owner_file assignments in buildSpawnCommand, and the identity values in
buildOwnedStaleTerminationCommand.
The remote shell strips only one quoting layer, so python received a
mutex path with literal quote characters in it (creating a directory
literally named ' in $HOME), and the payload's mkdir "$reservation"
loop spun on a path that can never exist. Every Desktop SSH backend
spawn hung until the connect timeout, retried, and left an orphaned
flock queue behind; stale-owner cleanup always printed REFUSED for the
same reason.
The regression test parses the composed command with a real sh — the
same parse the remote login shell performs — and requires the mutex
path and the payload's reservation paths to come out fully expanded.
Kolton Jacobs
63b77aa593