coder/code-server · error · Error

`yarn` is no longer supported; please use `npm install` inst

Error message

`yarn` is no longer supported; please use `npm install` instead

What it means

code-server's preinstall lifecycle hook rejects yarn to enforce a single package manager (npm) and prevent lockfile/dependency drift. It inspects process.env.npm_execpath (the path to the running package manager binary) and aborts the install if the path contains 'yarn'. This keeps CI and contributor installs deterministic.

Source

Thrown at ci/dev/preinstall.js:2

if (process.env.npm_execpath.includes("yarn")) {
  throw new Error("`yarn` is no longer supported; please use `npm install` instead")
}

View on GitHub (pinned to 51f90a376b)

Solutions

Run `npm install` (or `npm ci` for reproducible installs) instead of `yarn`
If a package-manager wrapper is forcing yarn, pin it to npm for this repo (e.g. `corepack enable && corepack use npm`) or uninstall the shim
Remove any committed yarn.lock / .yarnrc.yml so tooling does not auto-detect yarn

Example fix

// before
yarn install

// after
npm install

Defensive patterns

Strategy: validation

Validate before calling

// Run before invoking install in this repo
const execpath = process.env.npm_execpath || ""
if (execpath.includes("yarn")) {
  console.error("This repo requires npm. Re-run with: npm install")
  process.exit(1)
}
// Or detect the active manager up front:
const pkgManager = execpath.includes("yarn") ? "yarn"
  : execpath.includes("pnpm") ? "pnpm" : "npm"
if (pkgManager !== "npm") throw new Error(`Use npm, not ${pkgManager}`)

Prevention

Document `npm install` as the only supported install command in CONTRIBUTING/README
Do not commit a yarn.lock; tooling auto-detects yarn from its presence
In CI, invoke `npm ci` explicitly rather than relying on a generic install step

When it happens

Trigger: Running `yarn` or `yarn install` in the code-server repo root, which invokes npm lifecycle scripts with npm_execpath pointing at the yarn binary. Also triggered by any wrapper (corepack, volta, asdf) that routes `install` through yarn.

Common situations: New contributors whose global default is yarn; monorepo tooling that auto-detects yarn from a stray yarn.lock; CI images that ship yarn as the default `install` command.

AI-assisted analysis of coder/code-server@51f90a376b (2026-08-12). Data as JSON: /api/errors/2427a93400dccf8d. Report an issue: GitHub.