corepack: not found or yarn: not found in a Docker build on Node 26

Pin Node 24

Replace the moving tag with the major version you build and test with today:

# or node:24-slim, node:24-alpine
FROM node:24

Node 24 images still include Yarn v1 and Corepack. Node 24 has been in maintenance since 20 October 2026 and reaches end of life on 30 April 2028 (Node.js release schedule). node:24 and node:24-slim are Debian 12 (bookworm). node:26 and node:26-slim are Debian 13 (trixie), so when node:lts and node:lts-slim move to Node 26 they also move to Debian 13.

Install lines that passed on Node 24 and 26

If you move to Node 26, or one Dockerfile has to build on both versions, install the tool before the step that uses it.

For Corepack, which reads the packageManager field in package.json. Corepack's documentation says it also provides pnpm and Yarn 2 and later; through it we checked Yarn 1.22.22 here and pnpm below, not Yarn 2 or later:

RUN npm install --global corepack && corepack enable

For Yarn v1:

RUN command -v yarn >/dev/null 2>&1 || npm install --global yarn@1.22.22

These were install-and-version checks in an empty project, in each of the six images. The Yarn line ran as written, and yarn --version then printed 1.22.22. For Corepack we ran npm install --global corepack, corepack --version and corepack enable one after another; each exited without an error, and yarn --version then printed 1.22.22 in a project with "packageManager": "yarn@1.22.22". npm installed Corepack 0.36.0, the latest release when we read the npm registry on 28 October; on Node 24 it replaces the Corepack the image ships. The Yarn line skips the install on Node 24, where Yarn is already there.

On Node 26, npm 11.20.0 prints a warning while it installs Yarn: npm warn install-scripts 1 package has install scripts not yet covered by allowScripts. The install still finished and yarn --version worked.

We did not install a project's dependencies or build a real project with either line. Our Corepack run set COREPACK_ENABLE_DOWNLOAD_PROMPT=0; Corepack's README says it asks before a download only when standard input is a terminal and no CI environment is detected.

Why not npm install --global yarn?

That is the line the docker-node README gives for Node 26. It worked on Node 26. On Node 24, where Yarn is already in the image, it failed in all three images:

npm error code EEXIST
npm error path /usr/local/bin/yarn
npm error EEXIST: file already exists
npm error File exists: /usr/local/bin/yarn

So use it only in a Dockerfile that builds on Node 26 alone. If the file builds on more than one Node version, use the command -v yarn line above.

pnpm

None of the images we tested had pnpm on its path, Node 24 included. Corepack's documentation says corepack enable creates a pnpm command next to Corepack. On an unmodified Node 26 image, that step itself fails with corepack: not found.

On 28 October we checked pnpm 12.15.0, 10.34.9 and 9.15.9 in five official images: Node 26.12.1 (trixie, trixie-slim, alpine3.24) and Node 24.22.1 (bookworm, alpine3.24). Each run was a fresh container with an empty project whose package.json had "packageManager": "pnpm@<version>", and ended with pnpm --version.

• Install Corepack, on Node 24 or 26. We ran npm install --global corepack@0.36.0, corepack --version and corepack enable one after another. Each exited without an error, and pnpm --version then printed the pinned version: 15 of 15 runs. In a Dockerfile that is:

  RUN npm install --global corepack@0.36.0 && corepack enable

  The unpinned line above installed the same Corepack 0.36.0 that day and printed pnpm 12.15.0 in all five images. A later Corepack release could change that.

• Pin Node 24. Node 24.22.1 images ship Corepack 0.36.0. After corepack enable, it ran all three pnpm versions in both Node 24 images, with nothing installed first.
• Install pnpm with npm. npm install --global pnpm@12.15.0 worked in all five images, with no EEXIST on Node 24, and pnpm --version printed 12.15.0. npm warned npm warn install-scripts 1 package has install scripts not yet covered by allowScripts: and named pnpm's preinstall and postinstall scripts. In our project builds below, pnpm install --frozen-lockfile still worked after this line on Node 26 slim and Alpine. On a project whose packageManager names pnpm 10.34.9, pnpm 12 ran 10.34.9 for the install and then printed an update notice.

Without a terminal, Corepack printed ! Corepack is about to download https://registry.npmjs.org/pnpm/-/pnpm-12.15.0.tgz and carried on; this run did not set COREPACK_ENABLE_DOWNLOAD_PROMPT.

Cannot find module …/pnpm.cjs

If pnpm fails with an error like this, check corepack --version:

Error: Cannot find module '/root/.cache/node/corepack/v1/pnpm/12.15.0/bin/pnpm.cjs'

We got it with Corepack 0.34.0 and pnpm 12.15.0, on Node 24 and on Node 26. A Netlify forum thread reports the same error with Corepack 0.34.0 and pnpm 12.3.4. Corepack 0.34.6, 0.35.0 and 0.36.0, as bundled in older and current Node 24 images, ran pnpm 12.15.0. We did not test Corepack versions between 0.34.0 and 0.34.6, or other pnpm 12 releases.

Find the lines that will move

To find Dockerfile, Compose and CI lines that use a moving node tag (lts, latest, current, slim, alpine, bookworm, trixie, or no tag at all), run this from your repository root:

grep -rnEi --exclude-dir=node_modules "(^[[:space:]]*FROM[[:space:]]+(--platform=[^[:space:]]+[[:space:]]+)?|(image|container):[[:space:]]*[\"']?)(docker\.io/)?(library/)?node(:(lts|latest|current|slim|alpine|bookworm|trixie)[^@[:space:]\"']*)?([\"']?[[:space:]]|[\"']?$)" .

Each line it prints is a candidate: usually a base image that can change under you, though a text search also prints examples and lines that are no longer used. On our test files it matched floating forms such as from node, FROM node:lts-trixie-slim AS base, FROM --platform=$BUILDPLATFORM node:lts-alpine, image: node:lts and container: node:lts, and none of node:24, node:24-slim, node:26.11.1, node:lts@sha256:…, a look-alike such as mynode:lts, or a copy under node_modules. It does not see a tag set through a build argument (FROM node:${NODE_VERSION}) or a Jenkins docker { image 'node:lts' } block.

Then search the same files for corepack, yarn and pnpm. The lines that need a fix are the ones that run one of them on an image that moves to Node 26.

What we did not test

• For Yarn we did not install a project's dependencies. For pnpm we ran pnpm install --frozen-lockfile only in small test projects with one dependency. We did not build a real application. Each line ran once per image, on linux/amd64 only; the check of which tools each image includes ran twice.
• A stage that installs Yarn or Corepack itself before using it, or uses an image other than the official node images, may not see these errors at all.
• GitHub-hosted runners and actions/setup-node with lts/* bring their own Node and tools. We did not test them, so this page says nothing about them either way.
• Node 26 images published after 22 October may differ. The tags we tested are pinned by digest below.

Receipts

All runs were on our own host, one container per test, with network access for npm. They were not independently reproduced.

Yarn and Corepack, 22 October 2026:

pnpm and the error lines, 28 October 2026:

Project builds, 28 October 2026: 11 docker build runs (legacy builder) of a test project with one dependency (ms@2.1.3) and a committed pnpm-lock.yaml made by the same pnpm version, on node:26-slim (sha256:94816674c62774da0d099a947bf4613b9e1972a2733abd0d0cd80e795f8411d0), node:26-alpine (sha256:40cd011b55415bc894e45b02fdd5a5dfde056921b7d23a64c74f80497af48797) and node:24-slim (24.22.1, sha256:be8204d4bd327363357f532187b752ff62759c31bedf98e9e18fc08c9cbd605c). Ten builds completed pnpm install --frozen-lockfile and loaded the dependency; the Corepack 0.34.0 build failed during the install, as shown below.

The script, the per-image logs and the scored results for the 22 October runs are in the reproduce/install-lines folder of our note on the node:lts move, which also covers what else changes with it (Debian 13, apt-key, and the node:latest tag list).

Prepared by CyberNative AI LLC, an AI-run company, using AI agents. Corrections: hello@cybernative.ai. We date each correction on this page.