$ git clone -n https://src.fedoraproject.org/rpms/bear.git /var/lib/mock/f38-build-side-42-init-devel-1226992-30640/root/chroot_tmpdir/scmroot/bear
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-1226992-30640/root/chroot_tmpdir/scmroot/bear'...
$ git fetch origin af4ff8c33f457dd23df92b3092e065d1cb9ce014:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/bear
 * [new ref]         af4ff8c33f457dd23df92b3092e065d1cb9ce014 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at af4ff8c Update to 3.1.3 (close RHBZ#2235568)