$ git clone -n https://src.fedoraproject.org/rpms/rust-syn.git /var/lib/mock/f40-build-2717012-72720/root/chroot_tmpdir/scmroot/rust-syn
Cloning into '/var/lib/mock/f40-build-2717012-72720/root/chroot_tmpdir/scmroot/rust-syn'...
$ git fetch origin 37a5089dc0d3ee23e3b36ca304f2f4c7b090b9ff:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-syn
 * [new ref]         37a5089dc0d3ee23e3b36ca304f2f4c7b090b9ff -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 37a5089 Update to version 2.0.58; Fixes RHBZ#2269894