Since that became active, every "apt-get install" command gives me a few
errors; for example,
$ LC_ALL=C apt-get install doxygen -t experimental
...
Do you want to continue? [Y/n] y
...
Fetched 20.9 MB in 12s (1616 kB/s)
The config 'root' does not exist. Likely snapper is not configured.
See 'man snapper' for further instructions.
apt-listchanges: Lese Changelogs...
...
Setting up doxygen (1.8.12-1) ...
Processing triggers for libc-bin (2.23-5) ...
Invalid snapshot ''.
This is a bit distracting, at least. Perhaps the test shouldn't be "-x
snapper" but something more specific.