$ git clone -n https://src.fedoraproject.org/rpms/bigloo.git /var/lib/mock/f39-build-2255519-54252/root/chroot_tmpdir/scmroot/bigloo
Cloning into '/var/lib/mock/f39-build-2255519-54252/root/chroot_tmpdir/scmroot/bigloo'...
$ git fetch origin 9f4c3891c98018322c00000607b248373fc60efa:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/bigloo
 * [new ref]         9f4c3891c98018322c00000607b248373fc60efa -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9f4c389 Do not change build arches for stable Fedora