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{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Subpath imports (#) fail on Windows when package.json path \u003e= 260 chars (MAX_PATH)","articleBody":"### Version\n\nv24.12.0\n\n### Platform\n\n```text\nMicrosoft Windows NT 10.0.26200.0 x64\n```\n\n### Subsystem\n\n_No response_\n\n### What steps will reproduce the bug?\n\nI ran into this while running `pnpm dev` in a project with a deep `node_modules` path:\n\n```\nTypeError: Package import specifier \"#module-sync-enabled\" is not defined imported from\nC:\\Users\\...\\node_modules\\.pnpm\\@react-router+dev@7.13.0_...\\@react-router\\dev\\module-sync-enabled\\index.mjs\n```\n\nMinimal repro — save as `test.mjs` and run with `node test.mjs` on Windows (with `LongPathsEnabled`):\n\n```mjs\nimport fs from \"node:fs\";\nimport { createRequire } from \"node:module\";\nimport path from \"node:path\";\n\n// \\\\?\\ prefix bypasses MAX_PATH limit for Win32 file APIs\nconst lp = (p) =\u003e \"\\\\\\\\?\\\\\" + p;\nconst ok = (fn) =\u003e {\n\ttry { fn(); return \"OK\"; }\n\tcatch (e) { console.error(e); return \"FAIL\"; }\n};\n\nconst MAX = 259; // MAX_PATH (260) minus null terminator\nconst cwd = process.cwd();\nconst fixedLen = cwd.length + 2 + \"package.json\".length;\nconst results = {};\n\nfor (const target of [MAX, MAX + 1]) {\n\tconst dir = path.join(cwd, \"a\".repeat(target - fixedLen));\n\tconst dep = path.join(dir, \"node_modules\", \"dep\");\n\n\tfs.mkdirSync(lp(dep), { recursive: true });\n\tfs.writeFileSync(\n\t\tlp(path.join(dir, \"package.json\")),\n\t\tJSON.stringify({ imports: { \"#foo\": \"./foo.mjs\" } }),\n\t);\n\tfs.writeFileSync(lp(path.join(dir, \"foo.mjs\")), \"export default 1\\n\");\n\tfs.writeFileSync(\n\t\tlp(path.join(dep, \"package.json\")),\n\t\tJSON.stringify({ name: \"dep\", exports: { \".\": \"./index.mjs\" } }),\n\t);\n\tfs.writeFileSync(lp(path.join(dep, \"index.mjs\")), \"export default 1\\n\");\n\n\tconst { resolve } = createRequire(path.join(dir, \"_.mjs\"));\n\tresults[`${target} chars`] = {\n\t\t\"fs.access\": ok(() =\u003e fs.accessSync(lp(path.join(dir, \"package.json\")))),\n\t\t'resolve(\"dep\")': ok(() =\u003e resolve(\"dep\")),\n\t\t'resolve(\"#foo\")': ok(() =\u003e resolve(\"#foo\")),\n\t};\n\n\tfs.rmSync(lp(dir), { recursive: true, force: true });\n}\n\nconsole.table(results);\n```\n\n### How often does it reproduce? Is there a required condition?\n\nAlways reproduces when the package.json path is \u003e= 260 characters. Requires Windows with `LongPathsEnabled` set (so that other file operations work fine past MAX_PATH).\n\nCommon with deeply nested `node_modules` (e.g. pnpm `.pnpm` layout + tools that create deep directories like `.claude/worktrees`).\n\n### What is the expected behavior? Why is that the expected behavior?\n\nAll three operations should succeed at both path lengths:\n\n```\n┌───────────┬───────────┬────────────────┬─────────────────┐\n│ (index)   │ fs.access │ resolve(\"dep\") │ resolve(\"#foo\") │\n├───────────┼───────────┼────────────────┼─────────────────┤\n│ 259 chars │ 'OK'      │ 'OK'           │ 'OK'            │\n│ 260 chars │ 'OK'      │ 'OK'           │ 'OK'            │\n└───────────┴───────────┴────────────────┴─────────────────┘\n```\n\n`LongPathsEnabled` is set and both `fs` operations and subpath exports (which also resolve through package.json) work fine past MAX_PATH.\n\n### What do you see instead?\n\n```\n┌───────────┬───────────┬────────────────┬─────────────────┐\n│ (index)   │ fs.access │ resolve(\"dep\") │ resolve(\"#foo\") │\n├───────────┼───────────┼────────────────┼─────────────────┤\n│ 259 chars │ 'OK'      │ 'OK'           │ 'OK'            │\n│ 260 chars │ 'OK'      │ 'OK'           │ 'FAIL'          │\n└───────────┴───────────┴────────────────┴─────────────────┘\n```\n\n```\nTypeError [ERR_PACKAGE_IMPORT_NOT_DEFINED]: Package import specifier \"#foo\" is not defined imported from ...\\_.mjs\n```\n\nOnly subpath imports (#) fail. I suspect `GetPackageScopeConfig` in `src/node_modules.cc` is missing the `ToNamespacedPath` call that was added to other functions in #53294 (later refactored into `NormalizePath` in #60425).\n\n### Additional information\n\n_No response_","author":{"url":"https://github.com/wonu","@type":"Person","name":"wonu"},"datePublished":"2026-02-28T17:09:03.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":0},"url":"https://github.com/62043/node/issues/62043"}