$ git clone -n https://src.fedoraproject.org/rpms/mcstrans.git /var/lib/mock/f40-build-2104931-50574/root/chroot_tmpdir/scmroot/mcstrans
Cloning into '/var/lib/mock/f40-build-2104931-50574/root/chroot_tmpdir/scmroot/mcstrans'...
$ git fetch origin c2e2aad05660eabc6770c4ad829c9a7afa737a91:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/mcstrans
 * [new ref]         c2e2aad05660eabc6770c4ad829c9a7afa737a91 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c2e2aad SELinux userspace 3.6 release