$ git clone -n https://src.fedoraproject.org/rpms/polymake.git /var/lib/mock/f39-build-1586005-38167/root/chroot_tmpdir/scmroot/polymake
Cloning into '/var/lib/mock/f39-build-1586005-38167/root/chroot_tmpdir/scmroot/polymake'...
$ git fetch origin 4b2ddcb16e2f9164171f8f5a1c2b80cea4e9ef52:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/polymake
 * [new ref]         4b2ddcb16e2f9164171f8f5a1c2b80cea4e9ef52 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4b2ddcb Rebuilt for https://fedoraproject.org/wiki/Fedora_39_Mass_Rebuild