Is it bad to have no default target in a Makefile

Question

Is it bad practice to have something like:

all:

in a Makefile, to enforce the user to specify the target, and ignore the default one?

Answer 1

all is not necessarily the default target. The default target is the first one defined in your makefile. Also, if you leave an empty target as the default one (and are sure that there's no other all target with rules somewhere else in the makefile), make's behavior might be a little bit puzzling. I'd suggest to let the default behavior print an appropriate error message, such as:

error:
        @echo "Please choose one of the following target: compile, install, uninstall"
        @# Alternatively: "Please RTFI(nstall)F(ile)"
        @exit 2