ERR_REQUIRE_ESM: Cannot require() p-limit in CommonJS builds

[jacekplonka]

Description

The @pyroscope/nodejs package fails with ERR_REQUIRE_ESM when using the CommonJS build (dist/cjs) due to p-limit@7.x being an ESM-only module.

Error

Error [ERR_REQUIRE_ESM]: require() of ES Module /app/node_modules/@pyroscope/nodejs/node_modules/p-limit/index.js from /app/node_modules/@pyroscope/nodejs/dist/cjs/sourcemapper.js not supported.

Instead change the require of index.js in /app/node_modules/@pyroscope/nodejs/dist/cjs/sourcemapper.js to a dynamic import() which is available in all CommonJS modules.

at Object.<anonymous> (/app/node_modules/@pyroscope/nodejs/dist/cjs/sourcemapper.js:64:35)

Root Cause

1. p-limit was upgraded to ^7.2.0 in package.json in v0.4.8 (4cad0a4)
2. p-limit@7.x is ESM-only and cannot be require()'d
3. src/sourcemapper.ts line 27 has: import pLimit from 'p-limit';
4. TypeScript compiles this to require('p-limit') in the CommonJS build
5. Runtime fails because ESM modules cannot be required from CommonJS

Reproduction

Environment:

• @pyroscope/nodejs: 0.4.8+
• Node.js: 20.x or 22.x
• Module system: CommonJS

Steps:

1. Install @pyroscope/nodejs in a CommonJS project
2. Import and initialize the profiler
3. Error occurs when the module loads, regardless of configuration

Workaround

Downgrade or add to package.json:

"resolutions": {
  "p-limit": "3.1.0"
}

Impact

• Severity: High - breaks CommonJS environments
• Affected versions: 0.4.8+ (when p-limit was upgraded to 7.x)

[magandrez]

Is there any investigation or work put into this @jake-kramer ?

This is preventing any upgrade beyond 0.4.7

[jake-kramer]

Hi @jacekplonka @magandrez my understanding is that the latest minor versions for Node [20.x, 22.x, 24.x, 25.x] resolve this issue. Can you provide more details on exactly which Node version you are using? I could not reproduce on latest minor for v20 (20.20.0) or v22 (22.22.0).

[magandrez]

Hi @jacekplonka @magandrez my understanding is that the latest minor versions for Node [20.x, 22.x, 24.x, 25.x] resolve this issue. Can you provide more details on exactly which Node version you are using? I could not reproduce on latest minor for v20 (20.20.0) or v22 (22.22.0).

Hi @jake-kramer and thanks for getting back in short notice.

I was running v24.10.0 (which was failing at the time). I upgraded to v24.12.0 (LTS) and I cannot reproduce the build issue described by @jacekplonka . I did not tested with other branches.

Thanks!

[ofershap]

Opened #247 to fix this. Swaps p-limit for tiny-limit which ships both ESM and CJS, so the ERR_REQUIRE_ESM goes away without needing a newer Node version.