$ git clone -n https://src.fedoraproject.org/rpms/rubygem-rdoc.git /var/lib/mock/f45-build-35234-694/root/chroot_tmpdir/scmroot/rubygem-rdoc
Cloning into '/var/lib/mock/f45-build-35234-694/root/chroot_tmpdir/scmroot/rubygem-rdoc'...
$ git fetch origin ceb42571a9c09b3fa9293c83598dfcd6688bd6a7:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-rdoc
 * [new ref]         ceb42571a9c09b3fa9293c83598dfcd6688bd6a7 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ceb4257 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild