[worksonmine]

I stopped using which some time ago because while it worked fine to bootstrap Debian based distros I found out it wasn't included in arch. Since then I always default to command -v. I don't see the problem, it already wasn't portable and as can be seen in this thread including it gives the false impression that it was.

[asveikau]

My house has machines running FreeBSD, OpenBSD, Linux, Mac, and lastly some old '90s Unix I never power on. Those all have which.

The only portability wrinkle I've personally seen is that old Solaris behaved differently when the program isn't found. It would say "no $1 in $PATH" to stdout, whereas more recent systems just don't display anything.