make has some behaviors which are confusing, complicated, or make it
unsuitable for use as a general command runner.
One example is that under some circumstances,
make won’t actually run the
commands in a recipe. For example, if you have a file called
test and the
make will refuse to run your tests:
$ make test
make: `test' is up to date.
make assumes that the
test recipe produces a file called
test. Since this
file exists and the recipe has no other dependencies,
make thinks that it
doesn’t have anything to do and exits.
To be fair, this behavior is desirable when using
make as a build system, but
not when using it as a command runner. You can disable this behavior for
specific targets using
.PHONY target name,
but the syntax is verbose and can be hard to remember. The explicit list of
phony targets, written separately from the recipe definitions, also introduces
the risk of accidentally defining a new non-phony target. In
recipes are treated as if they were phony.
Other examples of
make’s idiosyncrasies include the difference between
:= in assignments, the confusing error messages that are produced if you
mess up your makefile, needing
$$ to use environment variables in recipes,
and incompatibilities between different flavors of