$ git clone -n https://src.fedoraproject.org/rpms/rubygem-jmespath.git /var/lib/mock/f45-build-35030-693/root/chroot_tmpdir/scmroot/rubygem-jmespath
Cloning into '/var/lib/mock/f45-build-35030-693/root/chroot_tmpdir/scmroot/rubygem-jmespath'...
$ git fetch origin 424c1fddddf894cb0429229002b80d44acdf2afa:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-jmespath
 * [new ref]         424c1fddddf894cb0429229002b80d44acdf2afa -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 424c1fd Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild