Checking current git branch with ifneq in Makefile

Question

I'm trying to get my makefile to check that it's running on the correct branch and throw and error if not.

I'm using ifneq to compare them and git rev-parse --abbrev-ref HEAD to get the checked out branch, but it will not see them as equal. How can I fix this?

Right now the the code looks like this:

ifneq ($(git rev-parse --abbrev-ref HEAD), master)
    $(error Not on branch master)
else
    git checkout gh-pages
    git merge master
    git checkout master
endif

Thanks.

Answer 1

There is no such make function as $(git ...), so that variable reference expands to the empty string. You're always running:

ifneq (, master)

which will be always true.

You want to use the shell GNU make function:

ifneq ($(shell git rev-parse --abbrev-ref HEAD),master)