This image bundles together the phpcs analysis tool with the PHPCompatiblity standard.
See:
docker run -v $PWD:/src sixbysix/phpcompatibility phpcs .
The above will scan the current directory for PHP compatibility issues with the following configuration options:
colorsonstandardPHPCompatibility
You may pass in any additional options as required (https://github.com/squizlabs/PHP_CodeSniffer/wiki/Usage), for example if you were analysing a Magento 1 codebase you may wish to only look for incompatibilities within the local codepool:
docker run -v $PWD:/src sixbysix/phpcompatibility phpcs app/code/local