Build Samples Solution failing on PR #569 (chore/typescript-7): typescript-eslint has no TS 7.0 support yet

[cratis-direct]

Diagnosis

The run in question (https://github.com/Cratis/Samples/actions/runs/34032783153) is not on main — it's on branch chore/typescript-7 / PR #569 ("Upgrade TypeScript to 7 (build failing — needs review)"). main's own Build Samples Solution runs are green (e.g. #34028300447, #34024508448), because main still pins typescript at 6.0.3, and .github/workflows/update-packages.yml deliberately excludes typescript from automated dependency updates:

npm-package-exclusions: typescript,@cratis/components

So there is nothing to fix on main — the workflow itself is healthy there.

Why PR #569 fails

Confirmed against the captured log: typescript resolves to 7.0.2 on that branch, and yarn lint:ci fails immediately in every frontend workspace with:

Error: typescript-eslint does not support TS 7.0.
    at Object.<anonymous> (node_modules/@typescript-eslint/eslint-plugin/dist/index.js:50:11)

This is a real, currently-unresolved upstream limitation, not a Samples misconfiguration:

• @typescript-eslint/eslint-plugin@8.69.0 (latest, and also latest canary 8.69.1-alpha.0) still declares "typescript": ">=4.8.4 <6.1.0" as a peer dependency — TS 7 is out of range.
• Upstream tracking issue typescript-eslint/typescript-eslint#10940 is open with no released fix (last updated 2026-07-09).

The other blocker PR #569 already documented is now resolved upstream

PR #569's own description and a maintainer comment flag a second blocker: @cratis/arc.vite's EmitMetadataPlugin used the classic TS Program/ts.sys API, which TS 7's native package no longer exposes, breaking yarn build (Vite). That was fixed and merged in Cratis/Arc#2340 (2026-07-15), which also ports rollup-plugin-typescript2 → rollup-plugin-swc3 and works around the @typescript-eslint peer-dependency conflict via an aliased typescript-for-eslint devDependency + a postinstall script that relinks it into @typescript-eslint's own dependency tree (since neither resolutions nor packageExtensions can override an already-declared peer dependency). @cratis/arc.vite@22.10.4 (published 2026-09-05, already what main consumes) includes this fix.

So the Vite-build blocker is gone for a fresh attempt. The typescript-eslint peer-dependency conflict remains, but Arc#2340 shows a working pattern for it.

Why this isn't a small patch to PR #569 as-is

chore/typescript-7 was created 2026-07-10 (before Arc#2340 merged) and has drifted significantly from main — its latest "merge main" commit is missing entire workspace folders that exist on main now (Arc/React, ModelFirst aren't present in the branch tree at all). Patching the branch in place isn't safe; a real fix means re-doing the TypeScript 7 bump fresh off current main, reapplying the typescript-for-eslint aliasing pattern from Arc, and re-verifying lint → compile → test → build across all three frontend workspaces (Arc/React, Library/Lending, Library/Members). That's a deliberate feature-sized change to an experimental branch a maintainer already marked "Draft ... needs review" — not something to force onto their open PR as an ad-hoc CI fix.

Recommendation

• No action needed on main — it is intentionally pinned and its CI is green.
• PR Upgrade TypeScript to 7 (build failing — needs review) #569 should either be rebased fresh off main and updated with the same typescript-for-eslint aliasing workaround Arc used (now proven viable since @cratis/arc.vite publishes the TS7-compatible build), or left closed/paused until typescript-eslint ships official TS 7 support (typescript-eslint/typescript-eslint#10940).
• Keep the typescript exclusion in update-packages.yml until one of the above happens.

---

Posted by Stagehand (AI) - an autonomous agent, not a person. Review accordingly.

Ref #590

[cratis-direct]

Recurrence on a fresh run

The same failure recurred on run 34219198156, triggered after main advanced to c403c0a and the bot auto-merged main into chore/typescript-7 (commit f121e9e8 → merge commit 1bb3ca5, PR #569 is still isDraft: true).

Re-verified against the fresh log:

• typescript still resolves to 7.0.2 on the branch (root package.json devDependency, unchanged from the original diagnosis).
• yarn lint:ci still fails identically in every frontend workspace with Error: typescript-eslint does not support TS 7.0. from @typescript-eslint/eslint-plugin@8.70.0 (bumped from 8.69.0 since this issue was filed, still no TS 7 support — typescript-eslint/typescript-eslint#10940 remains open).
• main's own Build Samples Solution runs remain green (confirmed 34218786340 on c403c0a, push event) — nothing to fix there.

No new information changes the analysis or recommendation above: this is still an upstream typescript-eslint limitation blocking a Draft PR, not something to patch in-place. Leaving as-is per the existing recommendation (rebase fresh off main with the typescript-for-eslint aliasing pattern, or wait for upstream TS 7 support).