$ git clone -n https://src.fedoraproject.org/rpms/rubygem-rspec-core.git /var/lib/mock/f41-build-side-1-2939875-35318/root/chroot_tmpdir/scmroot/rubygem-rspec-core
Cloning into '/var/lib/mock/f41-build-side-1-2939875-35318/root/chroot_tmpdir/scmroot/rubygem-rspec-core'...
$ git fetch origin 54535562029999ef258e4fc46084364111db8085:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-rspec-core
 * [new ref]         54535562029999ef258e4fc46084364111db8085 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5453556 3.13.1