A signal during ssh install now sends sftp a SIGTERM instead of killing it, so sftp stops the ssh it started, as ssh to already does for ssh. sftp also runs with a WaitDelay of a quarter second, so something it started that still holds its output cannot keep the tool waiting: the tool ends with status 1 and removes its working directory. The test's sftp stand-in now leaves such a child behind, and the test requires that within a second.
Judgement call: a session whose sftp ended well is not failed because something it started still holds its output when the WaitDelay is up, as the master ssh left by ControlPersist under -v does.
Model: opus-5-5