$ git clone -n https://src.fedoraproject.org/rpms/rubygem-stringex.git /var/lib/mock/f40-build-2071476-49322/root/chroot_tmpdir/scmroot/rubygem-stringex
Cloning into '/var/lib/mock/f40-build-2071476-49322/root/chroot_tmpdir/scmroot/rubygem-stringex'...
$ git fetch origin d447296d113a6f7c039c3e195fd700098929e5dc:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-stringex
 * [new ref]         d447296d113a6f7c039c3e195fd700098929e5dc -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d447296 remove patch