$ git clone -n https://src.fedoraproject.org/rpms/python-ujson.git /var/lib/mock/f38-build-729936-101953/root/chroot_tmpdir/scmroot/python-ujson
Cloning into '/var/lib/mock/f38-build-729936-101953/root/chroot_tmpdir/scmroot/python-ujson'...
$ git fetch origin 6bbb1d9c5fde2df4b38e31311ca1ab0ce7c8dec3:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/python-ujson
 * [new ref]         6bbb1d9c5fde2df4b38e31311ca1ab0ce7c8dec3 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6bbb1d9 Update to 5.8.0 (close RHBZ#2214034)