diagnose-config

Diagnose MegaLinter configuration. Read the .mega-linter.yml (or path provided in $ARGUMENTS) and check for:

1. Configuration hierarchy: Env vars override .mega-linter.yml, which overrides descriptor defaults. Both .mega-linter.yml and .megalinter.yml are recognized.
2. ENABLE/DISABLE conflicts: ENABLELINTERS/DISABLELINTERS take precedence over ENABLE/DISABLE (descriptor-level). You can't enable a linter if its descriptor is disabled.
3. Filter patterns: Validate FILTERREGEXINCLUDE/FILTERREGEXEXCLUDE regex syntax
4. Linter variable naming: Must be UPPERCASE with separator matching the generated name DESCRIPTORLINTERNAME (e.g., PYTHONPYLINTARGUMENTS, not pylint_arguments)
5. Flavor compatibility: If using a flavor image, verify the enabled linters exist in that flavor by checking flavors/<flavor>/flavor.json
6. EXTENDS: If using remote config inheritance via HTTPS URLs, verify they're accessible
7. APPLY_FIXES: Check the fix mode is compatible with the CI system — auto-commit requires write access to the branch
8. Pre/Post commands: Validate PRECOMMANDS and POSTCOMMANDS syntax (each needs command and cwd fields, cwd is root or workspace)
9. Common mistakes:

- Using lowercase linter names (must be UPPERCASE) - Missing separator in linter-specific vars - Setting VALIDATEALLCODEBASE=true in CI (slow — usually want diff-only) - Forgetting {LINTER}FILTERREGEXINCLUDE/EXCLUDE overrides global filters

Reference megalinter/config.py for the full resolution logic.