$ git clone -n https://src.fedoraproject.org/rpms/rust-cargo.git /var/lib/mock/f45-build-45131-821/root/chroot_tmpdir/scmroot/rust-cargo
Cloning into '/var/lib/mock/f45-build-45131-821/root/chroot_tmpdir/scmroot/rust-cargo'...
$ git fetch origin 6595c04053f50ebc2305043dec5c89e6a8688512:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-cargo
 * [new ref]         6595c04053f50ebc2305043dec5c89e6a8688512 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6595c04 Update to version 0.98.0; Fixes RHBZ#2366645