$ git clone -n https://src.fedoraproject.org/rpms/rust-tester.git /var/lib/mock/f38-build-side-42-init-devel-1395929-31050/root/chroot_tmpdir/scmroot/rust-tester
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-1395929-31050/root/chroot_tmpdir/scmroot/rust-tester'...
$ git fetch origin 6e0f3267d0a66549a4c443ebdbdfa9defa683125:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-tester
 * [new ref]         6e0f3267d0a66549a4c443ebdbdfa9defa683125 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6e0f326 Update to version 0.9.1; Fixes RHBZ#2190391