$ git clone -n https://src.fedoraproject.org/rpms/rust-primeorder.git /var/lib/mock/f39-build-1860933-42477/root/chroot_tmpdir/scmroot/rust-primeorder
Cloning into '/var/lib/mock/f39-build-1860933-42477/root/chroot_tmpdir/scmroot/rust-primeorder'...
$ git fetch origin 546c36394b8c4bb334a96013e8a43b1be762b3ed:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-primeorder
 * [new ref]         546c36394b8c4bb334a96013e8a43b1be762b3ed -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 546c363 Update to version 0.13.6; Fixes RHBZ#2249951