$ git clone -n https://src.fedoraproject.org/rpms/mir.git /var/lib/mock/f39-build-1563277-37477/root/chroot_tmpdir/scmroot/mir
Cloning into '/var/lib/mock/f39-build-1563277-37477/root/chroot_tmpdir/scmroot/mir'...
$ git fetch origin c0d7e72fc450f2f23d636bd793255b762f6888d2:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/mir
 * [new ref]         c0d7e72fc450f2f23d636bd793255b762f6888d2 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c0d7e72 Update to 2.15.0