$ git clone -n https://src.fedoraproject.org/rpms/libnss-mysql.git /var/lib/mock/f42-build-3282776-41399/root/chroot_tmpdir/scmroot/libnss-mysql
Cloning into '/var/lib/mock/f42-build-3282776-41399/root/chroot_tmpdir/scmroot/libnss-mysql'...
$ git fetch origin b2b638a63a4ab163fbab7e2451cca83e69f54df8:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libnss-mysql
 * [new ref]         b2b638a63a4ab163fbab7e2451cca83e69f54df8 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b2b638a Switch to a maintained version by saknopper