7edb024a

By: Tom Sydney Kerckhove <syd@cs-syd.eu>

Render the diff runner's progress line as coloured chunks

The diff-scoped runner's one-line "N changed hunks; selected M mutations"
message went out via plain `hPutStrLn`.  Render it through `[[Chunk]]` with
`hPutChunksLocaleWith` (cyan hunk count, green mutation count, correct
singular/plural), matching the coverage and mutation phases' coloured output.

The machine-readable stdout of `list-components` and the
`--mutation-coverage-list[-locations]` modes is intentionally left plain: it
is parsed by the driver and Nix harness, so it must not carry colour codes.

Timeline