$ git clone -n https://src.fedoraproject.org/rpms/python-fb-re2.git /var/lib/mock/f41-build-side-2-python-2693924-30279/root/chroot_tmpdir/scmroot/python-fb-re2
Cloning into '/var/lib/mock/f41-build-side-2-python-2693924-30279/root/chroot_tmpdir/scmroot/python-fb-re2'...
$ git fetch origin 381802dc0ba064c2c5e8947b364628d45d3d14ae:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/python-fb-re2
 * [new ref]         381802dc0ba064c2c5e8947b364628d45d3d14ae -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 381802d Retire the package