$ git clone -n https://src.fedoraproject.org/rpms/libXext.git /var/lib/mock/f40-build-2228200-53073/root/chroot_tmpdir/scmroot/libXext
Cloning into '/var/lib/mock/f40-build-2228200-53073/root/chroot_tmpdir/scmroot/libXext'...
$ git fetch origin 3933d26e807ac4403b49c8ff8f34948bc5e0ee2f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libXext
 * [new ref]         3933d26e807ac4403b49c8ff8f34948bc5e0ee2f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 3933d26 SPDX migration