$ git clone -n https://src.fedoraproject.org/rpms/rubygem-hikidoc.git /var/lib/mock/f45-build-34949-692/root/chroot_tmpdir/scmroot/rubygem-hikidoc
Cloning into '/var/lib/mock/f45-build-34949-692/root/chroot_tmpdir/scmroot/rubygem-hikidoc'...
$ git fetch origin 315e6fed38f64451d525f7cf0ea977ffa8d7049a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-hikidoc
 * [new ref]         315e6fed38f64451d525f7cf0ea977ffa8d7049a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 315e6fe Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild