$ git clone -n https://src.fedoraproject.org/rpms/pkgtreediff.git /var/lib/mock/f41-build-side-1-2753465-31224/root/chroot_tmpdir/scmroot/pkgtreediff
Cloning into '/var/lib/mock/f41-build-side-1-2753465-31224/root/chroot_tmpdir/scmroot/pkgtreediff'...
$ git fetch origin 4c9a55954cecb2167f7768577f84e30d5f076293:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/pkgtreediff
 * [new ref]         4c9a55954cecb2167f7768577f84e30d5f076293 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4c9a559 bump release