Xdebug, not X-Debug.
FWIW, I did a similar test with Xdebug 2, Xdebug 3, PCOV, and phpdbg : https://php.watch/articles/php-code-coverage-comparison
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Command Line Interface Guidelines
Good naming, consistency, clear communication, and discoverability. These are things that do not only apply to command line programs, but to general development as well. Read more