$ git clone -n https://src.fedoraproject.org/rpms/rubygem-simpleidn.git /var/lib/mock/f45-build-35319-694/root/chroot_tmpdir/scmroot/rubygem-simpleidn
Cloning into '/var/lib/mock/f45-build-35319-694/root/chroot_tmpdir/scmroot/rubygem-simpleidn'...
$ git fetch origin 73eb660263043a4af94ee6463e3340a604f57682:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-simpleidn
 * [new ref]         73eb660263043a4af94ee6463e3340a604f57682 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 73eb660 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild