this branch (in liveusb-creator repo) addresses a longtime bug that's
been very painful at least for some of us, when running the automated
test suite. I've also seen it once while doing a manual installation.
There's a .deb with these changes in the bugfix-6092-drop-racy-code
APT suite, and a debian_bugfix-6092-drop-racy-code branch in the
liveusb-creator Git repo (that shall be merged into the "debian"
branch there).
Note to RM: it would be good if this stuff was merged ASAP, as it's
kinda blocking our ongoing efforts at running our automated test suite
on our infrastructure.