$ git clone -n https://src.fedoraproject.org/rpms/rust-syn.git /var/lib/mock/f38-build-side-42-init-devel-1393402-30988/root/chroot_tmpdir/scmroot/rust-syn
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-1393402-30988/root/chroot_tmpdir/scmroot/rust-syn'...
$ git fetch origin 247bfbf575c8344be270d823e7f840ae9e603885:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-syn
 * [new ref]         247bfbf575c8344be270d823e7f840ae9e603885 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 247bfbf Update to version 2.0.34; Fixes RHBZ#2237048