$ git clone -n https://src.fedoraproject.org/rpms/rubygem-xmlparser.git /var/lib/mock/f41-build-746418-13355/root/chroot_tmpdir/scmroot/rubygem-xmlparser
Cloning into '/var/lib/mock/f41-build-746418-13355/root/chroot_tmpdir/scmroot/rubygem-xmlparser'...
$ git fetch origin f093edaf16d092b05a90c34fefde672ce33379a6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-xmlparser
 * [new ref]         f093edaf16d092b05a90c34fefde672ce33379a6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f093eda Eliminate use of obsolete %patchN syntax (#2283636)