$ git clone -n https://src.fedoraproject.org/rpms/rbm.git /var/lib/mock/f39-build-1489783-34502/root/chroot_tmpdir/scmroot/rbm
Cloning into '/var/lib/mock/f39-build-1489783-34502/root/chroot_tmpdir/scmroot/rbm'...
$ git fetch origin d851c8c21dcc172e4a33a8dffcf8b90f74e8dc13:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rbm
 * [new ref]         d851c8c21dcc172e4a33a8dffcf8b90f74e8dc13 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d851c8c Revert dnf to dnf5 migration