I'm currently hacking on Linux trying to run a sort of UML-style thing on macOS (please don't question my sanity :), and I've run into various issues stemming from macOS having a case-insensitive filesystem.
The one you run into immediately is: there are a number of files (mostly in netfilter) that have different uppercase and lowercase versions. net/netfilter/xt_DSCP.c and net/netfilter/xt_dscp.c are quite different. Last I checked, git would pseudo-randomly pick one of these to check out, and then show the other one as having unstaged changes making it look like the first one. This causes problems when switching branches. I've worked around this with a sparse checkout that excludes these files, but it's not great. The gitignore also contains the pattern *.s, which excludes *.S as well when git is ignoring case. Is there any interest in fixing these? ~Theodore