typo

src/cmd/partition.rs

@@ -59,7 +59,7 @@ pub fn run(argv: &[&str]) -> CliResult<()> {
  fs::create_dir_all(&args.arg_outdir)?;
 
  // It would be nice to support efficient parallel partitions, but doing
- // do would involve more complicated inter-thread communication, with
+ // so would involve more complicated inter-thread communication, with
  // multiple readers and writers, and some way of passing buffers
  // between them.
  args.sequential_partition()