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{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"`ERR_INTERNAL_ASSERTION` when `import()` and `require()` load the same ESM dependency","articleBody":"### Version\n\nv24.14.0\n\n### Platform\n\n```text\nDarwin parksb 24.4.0 Darwin Kernel Version 24.4.0: Wed Mar 19 21:17:37 PDT 2025; root:xnu-11417.101.15~1/RELEASE_ARM64_T6031 arm64\n```\n\n### Subsystem\n\n_No response_\n\n### What steps will reproduce the bug?\n\n1. Create an ESM-only package called `esm-dep`.\n1. Create a dual package called `dual-pkg` with conditional exports where the `\"import\"` entry (`esm.mjs`) does `import \"esm-dep\"` and the `\"require\"` entry (`cjs.js`) does `require(\"esm-dep\")`.\n1. Create a CJS package called `cjs-pkg` that does `require(\"dual-pkg\")`.\n1. Then run a CJS script that calls `import(\"dual-pkg\")` and `require(\"cjs-pkg\")` in the same synchronous tick.\n\n```js\n// index.cjs\nimport(\"dual-pkg\");\nrequire(\"cjs-pkg\");\n```\n\nA minimal reproduction is available at: https://github.com/parksb/nodejs-node-issue-62432\n\n```\n$ git clone https://github.com/parksb/nodejs-node-issue-62432.git\n$ cd nodejs-node-issue\n$ npm install\n$ nvm use 22\n$ node index.cjs # no error\n$ nvm use 24\n$ node index.cjs # ERR_INTERNAL_ASSERTION\n```\n\n### How often does it reproduce? Is there a required condition?\n\nAlways reproduces on v24.x. The repository includes `.nvmrc` pinned to v24.14.0. Switching to Node 22.x (`nvm use 22`) and re-running `node index.cjs` succeeds without error.\n\nThe required condition is that `import()` and `require()` resolve to different entry points of the same dual package (via conditional exports), and both entry points depend on the same ESM-only package (`esm-dep`). The two calls must happen in the same synchronous tick, with no `await` between them.\n\n### What is the expected behavior? Why is that the expected behavior?\n\nNo error. Both `import()` and `require()` should be able to load `esm-dep`. `require(esm)` has been supported since Node 22.12.0 for synchronous graphs without top-level await.\n\n### What do you see instead?\n\n```\nnode:internal/assert:17\n  throw new ERR_INTERNAL_ASSERTION(message);\n  ^\n\nError [ERR_INTERNAL_ASSERTION]: Unexpected module status 0. Cannot require() ES Module /Users/parksb/nodejs-node-issue/esm-dep/index.js because it is not yet fully loaded.\nThis may be caused by a race condition if the module is simultaneously dynamically import()-ed via Promise.all().\nTry await-ing the import() sequentially in a loop instead.\n (From /Users/parksb/nodejs-node-issue/dual-pkg/cjs.js in non-loader-hook thread)\nThis is caused by either a bug in Node.js or incorrect usage of Node.js internals.\nPlease open an issue with this stack trace at https://github.com/nodejs/node/issues\n\n    at assert.fail (node:internal/assert:17:9)\n    at ModuleLoader.importSyncForRequire (node:internal/modules/esm/loader:364:16)\n    at loadESMFromCJS (node:internal/modules/cjs/loader:1629:24)\n    at Module._compile (node:internal/modules/cjs/loader:1794:5)\n    at Object..js (node:internal/modules/cjs/loader:1943:10)\n    at Module.load (node:internal/modules/cjs/loader:1533:32)\n    at Module._load (node:internal/modules/cjs/loader:1335:12)\n    at wrapModuleLoad (node:internal/modules/cjs/loader:255:19)\n    at Module.require (node:internal/modules/cjs/loader:1556:12)\n    at require (node:internal/modules/helpers:152:16) {\n  code: 'ERR_INTERNAL_ASSERTION'\n}\n\nNode.js v24.14.1\n```\n\n### Additional information\n\nThese might be related: \n- https://github.com/nodejs/node/issues/55782\n- https://github.com/nodejs/node/pull/60380","author":{"url":"https://github.com/parksb","@type":"Person","name":"parksb"},"datePublished":"2026-03-25T11:52:30.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":3},"url":"https://github.com/62432/node/issues/62432"}