$ git clone -n https://src.fedoraproject.org/rpms/jakarta-saaj.git /var/lib/mock/f41-build-1204280-22444/root/chroot_tmpdir/scmroot/jakarta-saaj
Cloning into '/var/lib/mock/f41-build-1204280-22444/root/chroot_tmpdir/scmroot/jakarta-saaj'...
$ git fetch origin 3d1fd54f07fb2ef219b2387fce7e0068b0862b00:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/jakarta-saaj
 * [new ref]         3d1fd54f07fb2ef219b2387fce7e0068b0862b00 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 3d1fd54 Update to upstream version 3.0.2