## TL;DR

Fix: Maintainer iloveitaly (maintains railpack): this was platform-side, the mise yarn backend (asdf) was broken/corrupted for a period of time; Railpack later moved to a different mise backend via PR #216, but the asdf backend had already been fixed, so builds recovered on their own (`deploy again and it should be fixed`). Workarounds that reporters used meanwhile: pin the builder to NIXPACKS in railway.json, or switch the service to a Dockerfile that installs yarn directly (`npm i -g yarn@1.22.22`).

## The error

```text
Railway deploys via Railpack suddenly fail with `Failed to resolve version 1 of yarn` / `Failed to resolve version 1.22.22` even though nothing changed in the project, yarn 1.x detected via Corepack/mise, then version resolution fails.
```

## Fix

1. Maintainer iloveitaly (maintains railpack): this was platform-side, the mise yarn backend (asdf) was broken/corrupted for a period of time; Railpack later moved to a different mise backend via PR #216, but the asdf backend had already been fixed, so builds recovered on their own (`deploy again and it should be fixed`).
2. Workarounds that reporters used meanwhile: pin the builder to NIXPACKS in railway.json, or switch the service to a Dockerfile that installs yarn directly (`npm i -g yarn@1.22.22`).

Success check: the symptom above is gone and the original operation completes.

## When to use

- You hit this exact symptom in railpack.
- You want the verified fix without digging through the thread.

## When not to use

- A different error in railpack, even a similar-looking one.
- General railpack setup or credential questions.

## Compatibility

- Railpack (railwayapp/railpack) Reported against version 1.

## Variant phrasings

- How to fix "build Fails Due to “Failed to Resolve Version 1 of Yarn” Without Any Config Changes" in railpack
- railpack: build Fails Due to “Failed to Resolve Version 1 of Yarn” Without Any Config Changes
- build Fails Due to “problem to Resolve Version 1 of Yarn” Without Any Config Changes

## Source

- https://github.com/railwayapp/railpack/issues/210

---

## Vectle citations

- Exact version: <https://vectle.com/skills/skl_NiJOEqSzgNILNCYz1pud4w/versions/skv_gOib4HImUbnTpIMNmf6NPQ>
- Canonical HTML skill page: <https://vectle.com/skills/skl_NiJOEqSzgNILNCYz1pud4w>
- Current Markdown URL: <https://vectle.com/skills/skl_NiJOEqSzgNILNCYz1pud4w/markdown>

## Selected public attribution and original notices/references

```json
{
  "author": "issueatlas",
  "client": null,
  "notices_and_references": [
    "https://github.com/railwayapp/railpack/issues/210"
  ]
}
```