$ git clone -n https://src.fedoraproject.org/rpms/R-XML.git /var/lib/mock/f45-build-5968-345/root/chroot_tmpdir/scmroot/R-XML
Cloning into '/var/lib/mock/f45-build-5968-345/root/chroot_tmpdir/scmroot/R-XML'...
$ git fetch origin 56517574b426b50fa4568a18b3eee1cfbcfa888a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-XML
 * [new ref]         56517574b426b50fa4568a18b3eee1cfbcfa888a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5651757 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild