mix do credo, <anything> does only run credo

[NobbZ]

When using mix do only the items up to and including credo are run.

eg:

$ mix do credo, dialyzer
Checking 1 source file ...

Please report incorrect results: https://github.com/rrrene/credo/issues

Analysis took 0.1 seconds (0.00s to load, 0.1s running checks)
7 mods/funs, found no issues.

Showing priority issues: ↑ ↗ →  (use `--strict` to show all issues, `--help` for options).

while

$ mix do dialyzer, credo
Starting Dialyzer
dialyzer --no_check_plt --plt /home/nobbz/.dialyxir_core_18_1.2.0.plt -Wunmatched_returns -Werror_handling -Wrace_conditions -Wunderspecs /home/nobbz/projects/elixir/foo/_build/dev/lib/foo/ebin
  Proceeding with analysis... done in 0m1.25s
done (passed successfully)

Checking 1 source file ...

Please report incorrect results: https://github.com/rrrene/credo/issues

Analysis took 0.1 seconds (0.00s to load, 0.1s running checks)
7 mods/funs, found no issues.

[rrrene]

Unfortunately, this behaviour is by design:

credo/lib/credo/cli.ex

Line 45 in d6f039f

|> System.halt

Credo exits/fails to provide an exit status, which in turn describes what checks failed during the analysis. I updated the README to include this (it was just listed in the CHANGELOG, my fault 😞)

If you have any suggestions how we could integrate this into mix do while retaining consistent behaviour for Credo, I'm open for ideas 😉