$ git clone -n https://src.fedoraproject.org/rpms/polymake.git /var/lib/mock/f41-build-851675-166037/root/chroot_tmpdir/scmroot/polymake
Cloning into '/var/lib/mock/f41-build-851675-166037/root/chroot_tmpdir/scmroot/polymake'...
$ git fetch origin 57ab581c80e7c853e8432f2d60ec0aadda064068:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/polymake
 * [new ref]         57ab581c80e7c853e8432f2d60ec0aadda064068 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 57ab581 Rebuild for Singular 4.4.0p4