$ git clone -n https://src.fedoraproject.org/rpms/rust-tempfile.git /var/lib/mock/f40-build-2063954-49167/root/chroot_tmpdir/scmroot/rust-tempfile
Cloning into '/var/lib/mock/f40-build-2063954-49167/root/chroot_tmpdir/scmroot/rust-tempfile'...
$ git fetch origin 54844a38c48b885b1e1856bb87aa3a1e61971849:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-tempfile
 * [new ref]         54844a38c48b885b1e1856bb87aa3a1e61971849 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 54844a3 Update to version 3.8.1; Fixes RHBZ#2246452