I’ve set up a 2nd install of dt 4.2.0 under Mint 21.1 (yes, I know there are powerful arguments to support the assertion that this is not necessary, but …) by copying most of ~.config/darktable to ~.config/darktable-xxx, with the exception of darktablerc, *.db and the snap shots. I start the non-default install from the command line using the --configdir parameter. It all works to my satisfaction - I can run both installs of dt - one at a time, of course. but I get a couple of messages in the terminal which mean nothing to me. I see the following line, repeated:
sh: 1: git: not found.
What mistake have I made?