$ git clone -n https://src.fedoraproject.org/rpms/replacer.git /var/lib/mock/f40-build-2413179-60564/root/chroot_tmpdir/scmroot/replacer
Cloning into '/var/lib/mock/f40-build-2413179-60564/root/chroot_tmpdir/scmroot/replacer'...
$ git fetch origin 9eb56ef566ff6457f48825bbbaf219638bc11d6e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/replacer
 * [new ref]         9eb56ef566ff6457f48825bbbaf219638bc11d6e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9eb56ef Port to maven-plugin-annotations from Javadoc tags