$ git clone -n https://src.fedoraproject.org/rpms/erlang-js.git /var/lib/mock/f41-build-749627-13378/root/chroot_tmpdir/scmroot/erlang-js
Cloning into '/var/lib/mock/f41-build-749627-13378/root/chroot_tmpdir/scmroot/erlang-js'...
$ git fetch origin d9cff6d452b903514f008c9e4443485fc320627a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/erlang-js
 * [new ref]         d9cff6d452b903514f008c9e4443485fc320627a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d9cff6d Rebuild with a fixed Erlang macros