It was noticed when playing with #libup
```
> composer lint
Cannot create cache directory /cache/composer/repo/https---packagist.org/, or directory is not writable. Proceeding without cache
Cannot create cache directory /cache/composer/files/, or directory is not writable. Proceeding without cache
> parallel-lint --exclude vendor
PHP Parallel Lint version 0.9.1
-------------------------------
Usage:
parallel-lint [sa] [-p php] [-e ext] [-j num] [--exclude dir] [files or directories]
Options:
-p <php> Specify PHP-CGI executable to run (default: 'php').
-s, --short Set short_open_tag to On (default: Off).
-a, -asp Set asp_tags to On (default: Off).
-e <ext> Check only files with selected extensions separated by comma.
(default: php,php3,php4,php5,phtml)
--exclude Exclude directory. If you want exclude multiple directories, use
multiple exclude parameters.
-j <num> Run <num> jobs in parallel (default: 10).
--no-colors Disable colors in console output.
--json Output results as JSON string (require PHP 5.4).
--blame Try to show git blame for row with error.
--git <git> Path to Git executable to show blame message (default: 'git').
--stdin Load files and folder to test from standard input.
--ignore-fails Ignore failed tests.
-h, --help Print this help.
```
It just prints the help, it doesn't actually lint anything in mw core (as expected)
Extensions generally have the '.' in there...
```
parallel-lint . --exclude vendor --exclude node_modules
```