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.