$ git clone -n https://src.fedoraproject.org/rpms/rubygem-memoizer.git /var/lib/mock/f45-build-35042-693/root/chroot_tmpdir/scmroot/rubygem-memoizer
Cloning into '/var/lib/mock/f45-build-35042-693/root/chroot_tmpdir/scmroot/rubygem-memoizer'...
$ git fetch origin de1f89cb3a5d36c4f7d5a13d2359e3efe16c1ed3:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-memoizer
 * [new ref]         de1f89cb3a5d36c4f7d5a13d2359e3efe16c1ed3 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at de1f89c Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild