Volar fails to start on NixOS

[pompydev]

Vue - Official extension or vue-tsc version

3.2.2

VSCode version

1.107.1

Vue version

3.5.26

TypeScript version

5.9.3

System Info

System:
    OS: Linux 6.18 cpe:/o:nixos:nixos:26.05 26.05 (Yarara)
    CPU: (24) x64 AMD Ryzen 9 7900X 12-Core Processor
    Memory: 52.83 GB / 62.41 GB
    Container: Yes
    Shell: 5.9 - /run/current-system/sw/bin/zsh
  Binaries:
    Node: 24.12.0 - /nix/store/cikdc61gfwvdma6y0p9b5d5d448aqcv6-nodejs-24.12.0/bin/node
    npm: 11.6.2 - /nix/store/cikdc61gfwvdma6y0p9b5d5d448aqcv6-nodejs-24.12.0/bin/npm
    pnpm: 10.26.1 - /nix/store/61lr9izijvg30pcribjdxgjxvh3bysp4-pnpm-10.26.1/bin/pnpm
    bun: 1.3.5 - /nix/store/qgwwg2jr2yrksig72y9cmhj65bdcnxhn-bun-1.3.5/bin/bun
    Deno: 2.6.3 - /nix/store/67dia2211bw3jdmp9gyn0nq9r5pmwi43-deno-2.6.3/bin/deno
  Browsers:
    Brave Browser: 143.1.85.118

package.json dependencies

{
  "name": "test",
  "private": true,
  "type": "module",
  "scripts": {
    "build": "nuxt build",
    "dev": "nuxt dev",
    "generate": "nuxt generate",
    "preview": "nuxt preview"
  },
  "dependencies": {
    "@nuxt/content": "^3.11.0",
    "better-sqlite3": "^12.6.2",
    "nuxt": "^4.2.2"
  }
}

Steps to reproduce

1. Install NixOS
2. Create new nuxt project

   bun create nuxt@latest test
   

   • template: content
   • package manager: bun
   • init git repo: no
   • install modules: no
3. Open ./test/ with vscode
4. Install Vue.Volar v3.2.2
5. Observe how IntelliSense features such as Ctrl+Click is not working on files such as app/pages/[...slug].vue
6. Observe how IntelliSense features such as Ctrl+Click does work in .ts files

What is expected?

Vue IntelliSense works when Vue.Volar extension is installed and TypeScript IntelliSense is working.

What is actually happening?

Vue.Volar extension fails to start due to following error (from vscode "Extension Host" output):

2026-01-21 16:20:05.982 [error] Activating extension Vue.volar failed due to an error:
2026-01-21 16:20:05.982 [error] Error: ENOENT: no such file or directory, mkdir '/nix/store/5bh8mwn530jc3x3wzipqapmja594fjjy-vscode-extension-Vue-volar-3.2.2/share/vscode/extensions/Vue.volar/node_modules/vue-typescript-plugin-pack'
	at Object.mkdirSync (node:fs:1364:26)
	at bi (/nix/store/5bh8mwn530jc3x3wzipqapmja594fjjy-vscode-extension-Vue-volar-3.2.2/share/vscode/extensions/Vue.volar/dist/extension.js:388:14071)
	at Object.<anonymous> (/nix/store/5bh8mwn530jc3x3wzipqapmja594fjjy-vscode-extension-Vue-volar-3.2.2/share/vscode/extensions/Vue.volar/dist/extension.js:388:10373)
	at Module._compile (node:internal/modules/cjs/loader:1714:14)
	at Module._extensions..js (node:internal/modules/cjs/loader:1848:10)
	at Module.load (node:internal/modules/cjs/loader:1448:32)
	at Module._load (node:internal/modules/cjs/loader:1270:12)
	at c._load (node:electron/js2c/node_init:2:17993)
	at e._load (file:///nix/store/gwvsig0qzv7sl5c21q367mk5nwjks2ks-vscode-1.107.1/lib/vscode/resources/app/out/vs/workbench/api/node/extensionHostProcess.js:404:6048)
	at t._load (file:///nix/store/gwvsig0qzv7sl5c21q367mk5nwjks2ks-vscode-1.107.1/lib/vscode/resources/app/out/vs/workbench/api/node/extensionHostProcess.js:222:22598)
	at r._load (file:///nix/store/gwvsig0qzv7sl5c21q367mk5nwjks2ks-vscode-1.107.1/lib/vscode/resources/app/out/vs/workbench/api/node/extensionHostProcess.js:214:24094)
	at TracingChannel.traceSync (node:diagnostics_channel:328:14)
	at wrapModuleLoad (node:internal/modules/cjs/loader:244:24)
	at Module.require (node:internal/modules/cjs/loader:1470:12)
	at require (node:internal/modules/helpers:147:16)
	at Object.<anonymous> (/nix/store/5bh8mwn530jc3x3wzipqapmja594fjjy-vscode-extension-Vue-volar-3.2.2/share/vscode/extensions/Vue.volar/main.js:5:19)
	at Module._compile (node:internal/modules/cjs/loader:1714:14)
	at Module._extensions..js (node:internal/modules/cjs/loader:1848:10)
	at Module.load (node:internal/modules/cjs/loader:1448:32)
	at Module._load (node:internal/modules/cjs/loader:1270:12)
	at c._load (node:electron/js2c/node_init:2:17993)
	at e._load (file:///nix/store/gwvsig0qzv7sl5c21q367mk5nwjks2ks-vscode-1.107.1/lib/vscode/resources/app/out/vs/workbench/api/node/extensionHostProcess.js:404:6048)
	at t._load (file:///nix/store/gwvsig0qzv7sl5c21q367mk5nwjks2ks-vscode-1.107.1/lib/vscode/resources/app/out/vs/workbench/api/node/extensionHostProcess.js:222:22598)
	at r._load (file:///nix/store/gwvsig0qzv7sl5c21q367mk5nwjks2ks-vscode-1.107.1/lib/vscode/resources/app/out/vs/workbench/api/node/extensionHostProcess.js:214:24094)
	at TracingChannel.traceSync (node:diagnostics_channel:328:14)
	at wrapModuleLoad (node:internal/modules/cjs/loader:244:24)
	at Module.require (node:internal/modules/cjs/loader:1470:12)
	at require (node:internal/modules/helpers:147:16)
	at HX.Cb (file:///nix/store/gwvsig0qzv7sl5c21q367mk5nwjks2ks-vscode-1.107.1/lib/vscode/resources/app/out/vs/workbench/api/node/extensionHostProcess.js:253:1253)

Link to minimal reproduction

No response

Any additional comments?

The bug occurrs because /nix/store is read-only.
After a bit of bisecting, 3.0.8 appears to be the version where this bug was introduced. Downgrading to 3.0.7 fixed it for me.

[gm112]

Maybe it's this bit of code that is doing it?

language-tools/extensions/vscode/index.ts

Line 204 in 10d056b

fs.writeFileSync(tsPluginPackPath, `module.exports = require("${tsPluginPath}");`);

in 3.0.8. In the current main branch at the time of this writing, I found the same code here

language-tools/extensions/vscode/src/extension.ts

Line 279 in efc6882

fs.writeFileSync(tsPluginEntry, `module.exports = require(${JSON.stringify(tsPluginPath)});`);

I think the fix would be something along the lines of changing the tsPluginDir variable to make use https://code.visualstudio.com/api/references/vscode-api#ExtensionContext.globalStorageUri? I'm not an expert so maybe my suggestion is wrong, but I have recently gotten into learning Nix and had ran into this as well. :)

[n0099]

language-tools/extensions/vscode/src/extension.ts

Line 253 in 1932c1c

fs.mkdirSync(tsPluginDir, { recursive: true });

is added in 0b0dd73#diff-38a8cdcea685e6218370b8aff5558fcdaf4c140c1b9d9c506a3254deb9847079R253 which originally is a rolldown plugin in https://github.com/vuejs/language-tools/pull/5860/changes#diff-5c7b142fe2984b33720317af87851abae59417c720b6f58d5ccf988611c577fdL31-L44 that will mkdir and create file while compile time instead of runtime.

---

language-tools/extensions/vscode/src/extension.ts

Line 307 in 1932c1c

fs.mkdirSync(path.dirname(reactiveAnalysisPluginEntry), { recursive: true });

is added in aa0c551#diff-38a8cdcea685e6218370b8aff5558fcdaf4c140c1b9d9c506a3254deb9847079R307

---

These commits are appeared in https://github.com/vuejs/language-tools/releases/tag/v3.2.0 so I've tried rollback to its previous version https://github.com/vuejs/language-tools/releases/tag/v3.1.8 with

pkgs.nix4vscode.forOpenVsxVersion (config.programs.vscode.package.version) [ "vue.volar.3.1.8" ]

but gives me the same error msg from fs.writeFileSync():

[error] Error: EROFS: read-only file system, open '/nix/store/93qw4y2bgs869hr96c2rswljz7d5m5xs-vscode-extension-vue-volar-3.1.8/share/vscode/extensions/vue.volar/node_modules/vue-typescript-plugin-pack/index.js'
	at Object.writeFileSync (node:fs:2425:20)
	at Ti (/nix/store/93qw4y2bgs869hr96c2rswljz7d5m5xs-vscode-extension-vue-volar-3.1.8/share/vscode/extensions/vue.volar/dist/extension.js:524:14143)
	at Object.<anonymous> (/nix/store/93qw4y2bgs869hr96c2rswljz7d5m5xs-vscode-extension-vue-volar-3.1.8/share/vscode/extensions/vue.volar/dist/extension.js:524:10505)
	at Module._compile (node:internal/modules/cjs/loader:1714:14)
	at Module._extensions..js (node:internal/modules/cjs/loader:1848:10)
	at Module.load (node:internal/modules/cjs/loader:1448:32)
	at Module._load (node:internal/modules/cjs/loader:1270:12)
	at c._load (node:electron/js2c/node_init:2:17993)
	at e._load (file:///nix/store/r0i52215xmb6w4nr6yfzjypjnyba62bk-vscodium-1.106.27818/lib/vscode/resources/app/out/vs/workbench/api/node/extensionHostProcess.js:402:6573)
	at t._load (file:///nix/store/r0i52215xmb6w4nr6yfzjypjnyba62bk-vscodium-1.106.27818/lib/vscode/resources/app/out/vs/workbench/api/node/extensionHostProcess.js:220:28755)
	at r._load (file:///nix/store/r0i52215xmb6w4nr6yfzjypjnyba62bk-vscodium-1.106.27818/lib/vscode/resources/app/out/vs/workbench/api/node/extensionHostProcess.js:212:24901)
	at TracingChannel.traceSync (node:diagnostics_channel:328:14)
	at wrapModuleLoad (node:internal/modules/cjs/loader:244:24)
	at Module.require (node:internal/modules/cjs/loader:1470:12)
	at require (node:internal/modules/helpers:147:16)
	at xX._doLoadModule (file:///nix/store/r0i52215xmb6w4nr6yfzjypjnyba62bk-vscodium-1.106.27818/lib/vscode/resources/app/out/vs/workbench/api/node/extensionHostProcess.js:251:1632)

This is introduced in b274db2#diff-cce79de8ec5b3ab6619b199d7b3b295ad6fc95c958b5759a82e52b433f9b05f1R197 so only https://github.com/vuejs/language-tools/releases/tag/v3.0.7 is usable.