$ git clone -n https://src.fedoraproject.org/rpms/fbrnch.git /var/lib/mock/f42-build-side-1-3501711-45976/root/chroot_tmpdir/scmroot/fbrnch
Cloning into '/var/lib/mock/f42-build-side-1-3501711-45976/root/chroot_tmpdir/scmroot/fbrnch'...
$ git fetch origin 6927c0631472e72772ba8e26aa883f755b4aacb7:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/fbrnch
 * [new ref]         6927c0631472e72772ba8e26aa883f755b4aacb7 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6927c06 fixup changelog entry for unautospec: don't use macros!