matrix-to doesn't build with latest Yarn version

Open

#412 opened on Jul 9, 2026 2 comments 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

Dominant language: JavaScript
Stars: 1.4k
Forks: 318
PR merge metrics: No merged PRs in 30d

Description

When [updating](https://github.com/element-hq/sre-internal/issues/3576) Cloudflare Pages build to v3, the build failed. Cloudflare Pages v1 used Ubuntu20 with default Yarn v1.22.4 while Cloudflare Pages v3 is using Ubuntu22 with default Yarn v1.22.22.

Setting `YARN_VERSION=1.22.4` in Cloudflare succeed again with Pages build v3.

(Nodejs version was also automatically bumped to 22.16.0 but that doesn't seem cause any trouble)

Node version can be pinned with `.node-version` but Cloudflare doesn't [support](https://developers.cloudflare.com/pages/configuration/build-image/#limitations) reading yarn version from the repo yet.

So, no immediate issue but we have an old yarn version that will keep getting older hardcoded in Cloudflare.

```
2026-07-09T08:57:35.665406Z Error: Exit with error code: 1
2026-07-09T08:57:35.66581Z at ChildProcess. (/snapshot/dist/run-build.js)
2026-07-09T08:57:35.665916Z at Object.onceWrapper (node:events:652:26)
2026-07-09T08:57:35.666006Z at ChildProcess.emit (node:events:537:28)
2026-07-09T08:57:35.666068Z at ChildProcess._handle.onexit (node:internal/child_process:291:12)
2026-07-09T08:57:35.672537Z Failed: build command exited with code: 1
2026-07-09T08:57:36.484437Z Failed: error occurred while running build command
```

Contributor guide

Open the contributing guide

First steps

Read the whole issue, then the project's contributing guide.
Comment on the issue to say you are picking it up — it saves two people doing the same work.
Fork the repository and make your change on a branch.
Open a pull request that references the issue number.

Research direction

Start with the Cloudflare Pages build configuration and the repository's .node-version and package metadata, then reproduce the failure using the newer Yarn version. Check the project build entry point and dependency scripts for the incompatibility; done means the Pages v3 build succeeds without pinning Yarn 1.22.4.

Written by the indexing model from the issue text.

Assessment

Tech stack: javascript
Domain: build-system
Issue type: Bug
Difficulty: 3/5
Estimated time: 1-2 days
Activity status: Quiet
Clarity: Mostly clear
Newbie friendliness: 55/100