Update to current ESLint 10.x before 9.x EOL Aug 2026

[MikeMcC399]

Situation

• The repo is configured for ESLint 9.x
• ESLint 9.x transitions into EOL on 2026-08-06
• Linting config is external through "@yarnpkg/eslint-config": "^3.0.0" pinned to @yarnpkg/eslint-config@3.1.0 (current latest, published in Sep 2025)

Assessment

• @yarnpkg/eslint-config@3.1.0 is not compatible with ESLint 10.x

Attempting an update to ESLint 10.4.0 (current latest) produces an error:

TypeError: Error while loading rule 'arca/import-ordering': context.getSourceCode is not a function

The transient dependency eslint-plugin-arca belonging to @arcanis is outdated. It uses ESLint 7 in its devDependencies EOL 2022-04-09 and it uses the deprecated context.getSourceCode() (Source repo https://github.com/arcanis/eslint-plugin-arca).

• Deprecated in ESLint 9 in 2023
• Removed in ESLint 10

Options

1. Work with Yarn Berry to produce a new release of @yarnpkg/eslint-config, compatible with ESLint 10.x
2. Remove the external dependency @yarnpkg/eslint-config and create an equivalent ESLint configuration directly into the Corepack repo

[MikeMcC399]

This is also relevant before the formal EOL of ESLint 9.x. Even now, ESLint 10.x fixes don't generally get backported to ESLint 9.x.

Issue #837 (TypeError with ESLint) was resolved through #847 by migrating from nodeLinker: pnp to the classic nodeLinker: node-modules on May 15, 2026.

eslint@10.3.0, released May 1, 2026 mitigated the issue, however this could not be used in the short-term, since the repo is fixed at ESLint 9.x.