Version
v22.22.3 through v22.23.1
Platform
Darwin LMJ6QJLXY 25.5.0 Darwin Kernel Version 25.5.0: Mon Apr 27 20:41:12 PDT 2026; root:xnu-12377.121.6~2/RELEASE_ARM64_T6050 arm64
Subsystem
No response
What steps will reproduce the bug?
#!/usr/bin/env bash
#
# Save this script to a file named `repro.sh`, then run it:
#
# bash repro.sh
#
# Without an argument, the script creates `node-yarn-pnp-repro` in the
# directory from which the script is run.
#
# Or choose the directory where the test project will be created:
#
# bash repro.sh ./my-pnp-repro
set -euo pipefail
repro_dir="${1:-node-yarn-pnp-repro}"
if [[ -e "$repro_dir" ]]; then
echo "Directory already exists: $repro_dir" >&2
exit 1
fi
mkdir "$repro_dir"
cd "$repro_dir"
echo "Reproduction directory: $PWD"
cat > package.json <<'EOF'
{
"name": "node-yarn-pnp-repro",
"private": true,
"packageManager": "yarn@4.16.0",
"dependencies": {
"autoprefixer": "10.4.2",
"css-loader": "7.1.4",
"postcss": "8.4.49",
"postcss-loader": "8.2.1",
"style-loader": "4.0.0",
"tailwindcss": "3.4.15",
"webpack": "5.108.1",
"webpack-cli": "5.1.4"
}
}
EOF
cat > .yarnrc.yml <<'EOF'
nodeLinker: pnp
enableGlobalCache: false
EOF
cat > tailwind.config.js <<'EOF'
module.exports = {
content: ['./src/**/*.html'],
theme: { extend: {} },
plugins: [],
};
EOF
cat > postcss.config.js <<'EOF'
module.exports = {
plugins: {
tailwindcss: {},
autoprefixer: {},
},
};
EOF
mkdir src
cat > src/style.css <<'EOF'
@tailwind base;
@tailwind components;
@tailwind utilities;
EOF
cat > src/index.html <<'EOF'
<div class="text-red-500">hi</div>
EOF
cat > webpack.config.js <<'EOF'
const path = require('path');
module.exports = {
mode: 'production',
entry: './src/style.css',
output: {
path: path.resolve(__dirname, 'dist'),
filename: 'bundle.js',
},
module: {
rules: [
{
test: /\.css$/,
use: ['style-loader', 'css-loader', 'postcss-loader'],
},
],
},
};
EOF
corepack yarn install
corepack yarn webpackHow often does it reproduce? Is there a required condition?
Every time with nodeLinker: pnp.
The same project succeeds with nodeLinker: node-modules on the same affected Node.js version.
What is the expected behavior? Why is that the expected behavior?
The build should succeed, as it does on Node.js v22.22.2 and earlier, and on Node.js v24.16.0 and later.
require.cache is documented as an object containing cached CommonJS modules.
Packages using Yarn PnP should continue to receive a require function with the standard CommonJS properties, including require.cache and require.extensions.
What do you see instead?
The build fails while webpack-cli loads webpack.config.js:
[webpack-cli] TypeError: Cannot convert undefined or null to object at Function.keys (<anonymous>) at exports.prepare (.../rechoir/index.js:21:14) at loadConfigByPath (.../webpack-cli/lib/webpack-cli.js:...) ...
rechoir calls Object.keys(require.extensions) at that location. Under Yarn PnP on affected Node.js versions, require.extensions is undefined.
The same underlying issue affects packages that access require.cache; for example, code such as delete require.cache[filePath] fails because require.cache is undefined.
Additional information
No response
Version
v22.22.3 through v22.23.1
Platform
Subsystem
No response
What steps will reproduce the bug?
How often does it reproduce? Is there a required condition?
Every time with nodeLinker: pnp.
The same project succeeds with nodeLinker: node-modules on the same affected Node.js version.
What is the expected behavior? Why is that the expected behavior?
The build should succeed, as it does on Node.js v22.22.2 and earlier, and on Node.js v24.16.0 and later.
require.cache is documented as an object containing cached CommonJS modules.
Packages using Yarn PnP should continue to receive a require function with the standard CommonJS properties, including require.cache and require.extensions.
What do you see instead?
The build fails while webpack-cli loads webpack.config.js:
[webpack-cli] TypeError: Cannot convert undefined or null to object at Function.keys (<anonymous>) at exports.prepare (.../rechoir/index.js:21:14) at loadConfigByPath (.../webpack-cli/lib/webpack-cli.js:...) ...rechoir calls Object.keys(require.extensions) at that location. Under Yarn PnP on affected Node.js versions, require.extensions is undefined.
The same underlying issue affects packages that access require.cache; for example, code such as delete require.cache[filePath] fails because require.cache is undefined.
Additional information
No response