$ git clone -n https://src.fedoraproject.org/rpms/papers.git /var/lib/mock/f41-build-side-1-3096517-39317/root/chroot_tmpdir/scmroot/papers
Cloning into '/var/lib/mock/f41-build-side-1-3096517-39317/root/chroot_tmpdir/scmroot/papers'...
$ git fetch origin 16ca178b1d2067cad4d888863c601ef53f786785:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/papers
 * [new ref]         16ca178b1d2067cad4d888863c601ef53f786785 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 16ca178 Co-own /usr/share/thumbnailers directory