$ git clone -n https://src.fedoraproject.org/rpms/perl-XML-LibXML.git /var/lib/mock/f40-build-2243972-53701/root/chroot_tmpdir/scmroot/perl-XML-LibXML
Cloning into '/var/lib/mock/f40-build-2243972-53701/root/chroot_tmpdir/scmroot/perl-XML-LibXML'...
$ git fetch origin f550798a453bb9304476aab14c1f250443b545ed:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-XML-LibXML
 * [new ref]         f550798a453bb9304476aab14c1f250443b545ed -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f550798 Fix-copying-external-entity-from-an-ext_ent_handler-.patch accepted