# ESLint flat config command line flags no longer available --ext --rulesdir --resolve-plugins-relative-to

Status: search-observed
Product: ESLint
Last verified: 2026-06-25
Canonical HTML: https://gitdocs.org/fix/eslint-flat-config-command-line-flags-no-longer-available-ext-rulesdir-resolve-plugins-relative
Machine JSON: https://gitdocs.org/api/fixes/eslint-flat-config-command-line-flags-no-longer-available-ext-rulesdir-resolve-plugins-relative.json

## Exact Symptom

See the observed Codex queries below.

## Diagnosis

The old package/config name is syntactically valid, but current tool packaging and discovery rules live in external release documentation.

## Fix

```
Verifier checks the current package identity/config format and a real transformed output. Check the exact intended lint findings, not merely process exit 0.
```

## Avoid

- Changing local code without checking the current external contract.
- Retrying the same install, build, or API call with no version/source change.
- Applying a broad unsafe bypass when a narrow compatibility fix is available.

## Observed Codex Queries

- ESLint flat config command line flags no longer available --ext --rulesdir --resolve-plugins-relative-to
- site:eslint.org docs latest use command line interface flat config --ext no longer available
- https://eslint.org/docs/latest/use/configure/migration-guide
- https://eslint.org/docs/v9.x/use/configure/migration-guide#cli-flag-changes
- eslint v9 migration guide CLI Flag Changes --ext
- ESLint "Invalid option '--ext'" flat config no longer supported
- https://eslint.org/docs/v8.x/use/configure/configuration-files-new#cli-flag-changes
- site:eslint.org/docs/v8.x/use/configure/configuration-files-new CLI Flag Changes --ext flat config

## Sources

- ESLint v10.0.0: https://eslint.org/blog/2026/02/eslint-v10.0.0-released/
- Official reference opened by Codex: https://eslint.org/docs/latest/use/configure/migration-guide
- Official reference opened by Codex: https://eslint.org/docs/v9.x/use/configure/migration-guide#cli-flag-changes
- Official reference opened by Codex: https://eslint.org/docs/v8.x/use/configure/configuration-files-new#cli-flag-changes