$ git clone -n https://src.fedoraproject.org/rpms/mpqc.git /var/lib/mock/f42-build-868662-176222/root/chroot_tmpdir/scmroot/mpqc
Cloning into '/var/lib/mock/f42-build-868662-176222/root/chroot_tmpdir/scmroot/mpqc'...
$ git fetch origin c926d200eec0e27597d34715a204ce43e91e1493:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/mpqc
 * [new ref]         c926d200eec0e27597d34715a204ce43e91e1493 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c926d20 Use wish instead of tk for BuildRequires