$ git clone -n https://src.fedoraproject.org/rpms/g2clib.git /var/lib/mock/f42-build-3275684-41321/root/chroot_tmpdir/scmroot/g2clib
Cloning into '/var/lib/mock/f42-build-3275684-41321/root/chroot_tmpdir/scmroot/g2clib'...
$ git fetch origin d0c94e7e6fb34956c69fc4be1b5a850efc3cf883:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/g2clib
 * [new ref]         d0c94e7e6fb34956c69fc4be1b5a850efc3cf883 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d0c94e7 Drop i686 builds