Clicking the Voxtype or fingerprint invitation did nothing. The launcher
execs setsid, which forks because the transient unit's main process is
already a process group leader, so the unit exits within milliseconds and
systemd's default control-group kill took the still-starting terminal down
with it. Run those units with KillMode=process instead.
The invitation tests had also drifted from the two-unit design and were
failing; teach the systemd-run mock to run the command it is given.
David Heinemeier Hansson