An interesting problem I encountered when moving to use Linux more is that git aliases are often run in POSIX sh instead of the terminal in use, such as bash or zsh. A few of my aliases are complex enough to require running an external shell command, ie using !. Some of those have complex comparisons or verify with the user what they are doing. I had long used some bashisms to simplify these, and didn’t have problems on my Mac, which uses bash as the sh implementation, but had problems in Ubuntu, which uses dash.