$ git clone -n https://src.fedoraproject.org/rpms/Rex.git /var/lib/mock/f41-build-side-1-2908106-34731/root/chroot_tmpdir/scmroot/Rex
Cloning into '/var/lib/mock/f41-build-side-1-2908106-34731/root/chroot_tmpdir/scmroot/Rex'...
$ git fetch origin 0f56b1038d01e091fb63635f621c65fe12960758:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/Rex
 * [new ref]         0f56b1038d01e091fb63635f621c65fe12960758 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 0f56b10 convert ASL 2.0 license to SPDX