$ git clone -n https://src.fedoraproject.org/rpms/buildah.git /var/lib/mock/f42-build-side-1-3499538-45965/root/chroot_tmpdir/scmroot/buildah
Cloning into '/var/lib/mock/f42-build-side-1-3499538-45965/root/chroot_tmpdir/scmroot/buildah'...
$ git fetch origin 81d952b145ef358b3c7c7718fe52da90003317b9:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/buildah
 * [new ref]         81d952b145ef358b3c7c7718fe52da90003317b9 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 81d952b Update to 1.39.4 upstream release