$ git clone -n https://src.fedoraproject.org/rpms/mgarepo.git /var/lib/mock/f41-build-side-2-python-2708478-30473/root/chroot_tmpdir/scmroot/mgarepo
Cloning into '/var/lib/mock/f41-build-side-2-python-2708478-30473/root/chroot_tmpdir/scmroot/mgarepo'...
$ git fetch origin ebdd899a0a5c4ef46e007c75c6e60195ee12dfc6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/mgarepo
 * [new ref]         ebdd899a0a5c4ef46e007c75c6e60195ee12dfc6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ebdd899 convert GPLv2+ license to SPDX