Module not found: Error can't resolve 'child_process', how to fix?

Question

I'm trying to create a JupyterLab extension, it uses typescript.

I've successfully added the package "@types/node" allowing me to use packages such as 'require('http')'.

But as soon as I try to use child process, using 'require("child_process")' I get the following error when trying to build the extension.

ModuleNotFoundError: Module not found: Error: Can't resolve 'child_process' in '/home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/jupyerlab_xkdc/lib'     at factory.create (/home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/webpack/lib/Compilation.js:535:10)     at factory (/home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/webpack/lib/NormalModuleFactory.js:397:22)     at resolver (/home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/webpack/lib/NormalModuleFactory.js:130:21)     at asyncLib.parallel (/home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/webpack/lib/NormalModuleFactory.js:224:22)     at /home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/neo-async/async.js:2825:7     at /home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/neo-async/async.js:6886:13     at normalResolver.resolve (/home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/webpack/lib/NormalModuleFactory.js:214:25)     at doResolve (/home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/enhanced-resolve/lib/Resolver.js:184:12)     at hook.callAsync (/home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/enhanced-resolve/lib/Resolver.js:238:5)     at _fn0 (eval at create (/home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/tapable/lib/HookCodeFactory.js:32:10), <anonymous>:15:1)     at resolver.doResolve (/home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/enhanced-resolve/lib/UnsafeCachePlugin.js:37:5)     at hook.callAsync (/home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/enhanced-resolve/lib/Resolver.js:238:5)     at _fn0 (eval at create (/home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/tapable/lib/HookCodeFactory.js:32:10), <anonymous>:15:1)     at hook.callAsync (/home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/enhanced-resolve/lib/Resolver.js:238:5)     at _fn0 (eval at create (/home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/tapable/lib/HookCodeFactory.js:32:10), <anonymous>:12:1)     at resolver.doResolve (/home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/enhanced-resolve/lib/DescriptionFilePlugin.js:42:38)     at hook.callAsync (/home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/enhanced-resolve/lib/Resolver.js:238:5)     at _fn41 (eval at create (/home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/tapable/lib/HookCodeFactory.js:32:10), <anonymous>:381:1)     at resolver.doResolve (/home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/enhanced-resolve/lib/ModuleKindPlugin.js:23:37)     at hook.callAsync (/home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/enhanced-resolve/lib/Resolver.js:238:5)     at _fn0 (eval at create (/home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/tapable/lib/HookCodeFactory.js:32:10), <anonymous>:15:1)     at hook.callAsync (/home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/enhanced-resolve/lib/Resolver.js:238:5)     at _fn0 (eval at create (/home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/tapable/lib/HookCodeFactory.js:32:10), <anonymous>:15:1)     at args (/home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/enhanced-resolve/lib/forEachBail.js:30:14)     at hook.callAsync (/home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/enhanced-resolve/lib/Resolver.js:238:5)     at _fn0 (eval at create (/home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/tapable/lib/HookCodeFactory.js:32:10), <anonymous>:15:1)     at resolver.doResolve (/home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/enhanced-resolve/lib/UnsafeCachePlugin.js:37:5)     at hook.callAsync (/home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/enhanced-resolve/lib/Resolver.js:238:5)     at _fn0 (eval at create (/home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/tapable/lib/HookCodeFactory.js:32:10), <anonymous>:15:1)     at hook.callAsync (/home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/enhanced-resolve/lib/Resolver.js:238:5) resolve 'child_process' in '/home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/jupyerlab_xkdc/lib' Parsed request is a module   using description file: /home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/jupyerlab_xkdc/package.json (relative path: ./lib)     Field 'browser' doesn't contain a valid alias configuration     resolve as module       /home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/jupyerlab_xkdc/lib/node_modules doesn't exist or is not a directory       /home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/node_modules doesn't exist or is not a directory       /home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/node_modules doesn't exist or is not a directory       /home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/node_modules doesn't exist or is not a directory       /home/fionn/anaconda3/envs/jupyterlab-ext/share/node_modules doesn't exist or is not a directory       /home/fionn/anaconda3/envs/jupyterlab-ext/node_modules doesn't exist or is not a directory       /home/fionn/anaconda3/envs/node_modules doesn't exist or is not a directory       /home/fionn/anaconda3/node_modules doesn't exist or is not a directory       /home/fionn/node_modules doesn't exist or is not a directory       /home/node_modules doesn't exist or is not a directory       /node_modules doesn't exist or is not a directory       looking for modules in /home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/jupyerlab_xkdc/node_modules         using description file: /home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/jupyerlab_xkdc/package.json (relative path: ./node_modules)           Field 'browser' doesn't contain a valid alias configuration       looking for modules in /home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules         using description file: /home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/package.json (relative path: ./node_modules)           Field 'browser' doesn't contain a valid alias configuration           using description file: /home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/child_process/package.json (relative path: .)             no extension               Field 'browser' doesn't contain a valid alias configuration           using description file: /home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/jupyerlab_xkdc/package.json (relative path: ./node_modules/child_process)             no extension               Field 'browser' doesn't contain a valid alias configuration               /home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/child_process is not a file             .wasm               Field 'browser' doesn't contain a valid alias configuration               /home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/jupyerlab_xkdc/node_modules/child_process doesn't exist             .wasm               Field 'browser' doesn't contain a valid alias configuration               /home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/child_process.wasm doesn't exist             .mjs               Field 'browser' doesn't contain a valid alias configuration               /home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/jupyerlab_xkdc/node_modules/child_process.wasm doesn't exist             .mjs               Field 'browser' doesn't contain a valid alias configuration               /home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/child_process.mjs doesn't exist             .js               Field 'browser' doesn't contain a valid alias configuration               /home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/jupyerlab_xkdc/node_modules/child_process.mjs doesn't exist             .js               Field 'browser' doesn't contain a valid alias configuration               /home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/child_process.js doesn't exist             .json               Field 'browser' doesn't contain a valid alias configuration               /home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/jupyerlab_xkdc/node_modules/child_process.js doesn't exist             .json               Field 'browser' doesn't contain a valid alias configuration               /home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/child_process.json doesn't exist               /home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/jupyerlab_xkdc/node_modules/child_process.json doesn't exist             as directory               existing directory                 use ./index.js from main in package.json                   using description file: /home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/child_process/package.json (relative path: .)                     Field 'browser' doesn't contain a valid alias configuration             as directory               /home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/jupyerlab_xkdc/node_modules/child_process doesn't exist                     using description file: /home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/child_process/package.json (relative path: ./index.js)                       no extension                         Field 'browser' doesn't contain a valid alias configuration                         /home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/child_process/index.js doesn't exist                       .wasm                         Field 'browser' doesn't contain a valid alias configuration                         /home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/child_process/index.js.wasm doesn't exist                       .mjs                         Field 'browser' doesn't contain a valid alias configuration                         /home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/child_process/index.js.mjs doesn't exist                       .js                         Field 'browser' doesn't contain a valid alias configuration                         /home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/child_process/index.js.js doesn't exist                       .json                         Field 'browser' doesn't contain a valid alias configuration                         /home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/child_process/index.js.json doesn't exist                       as directory                         /home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/child_process/index.js doesn't exist                 using path: /home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/child_process/index                   using description file: /home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/child_process/package.json (relative path: ./index)                     no extension                       Field 'browser' doesn't contain a valid alias configuration                       /home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/child_process/index doesn't exist                     .wasm                       Field 'browser' doesn't contain a valid alias configuration                       /home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/child_process/index.wasm doesn't exist                     .mjs                       Field 'browser' doesn't contain a valid alias configuration                       /home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/child_process/index.mjs doesn't exist                     .js                       Field 'browser' doesn't contain a valid alias configuration                       /home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/child_process/index.js doesn't exist                     .json                       Field 'browser' doesn't contain a valid alias configuration                       /home/fionn/anaconda3/envs/jupyterlab-ext/share/jupyter/lab/staging/node_modules/child_process/index.json doesn't exist error Command failed with exit code 1. 

I've googled around but still have no idea what to do to resolve this issue.

Any pointers or info at all would be greatly appreciated.

My packages.json file.

{   "name": "jupyerlab_xkdc",   "version": "0.1.0",   "description": "Short description",   "keywords": [     "jupyter",     "jupyterlab",     "jupyterlab-extension"   ],   "homepage": "https://github.com/my_name/myextension",   "bugs": {     "url": "https://github.com/my_name/myextension/issues"   },   "license": "BSD-3-Clause",   "author": "Fionn McKnight",   "files": [     "lib/**/*.{d.ts,eot,gif,html,jpg,js,js.map,json,png,svg,woff2,ttf}",     "style/**/*.{css,eot,gif,html,jpg,json,png,svg,woff2,ttf}"   ],   "main": "lib/index.js",   "types": "lib/index.d.ts",   "repository": {     "type": "git",     "url": "https://github.com/my_name/myextension.git"   },   "scripts": {     "build": "tsc",     "clean": "rimraf lib",     "prepare": "npm run clean && npm run build",     "watch": "tsc -w"   },   "dependencies": {     "@jupyterlab/application": "^0.19.1",     "@jupyterlab/apputils": "^0.19.1",     "@phosphor/coreutils": "^1.3.0",     "@phosphor/messaging": "^1.2.2",     "@phosphor/widgets": "^1.6.0",     "@types/jquery": "^3.3.29",     "@types/node": "^10.12.19",     "child_process": "^1.0.2",     "npm": "^6.7.0"   },   "devDependencies": {     "@types/node": "^10.12.19",     "rimraf": "^2.6.1",     "typescript": "~3.1.1"   },   "jupyterlab": {     "extension": true   } } 

Answer 1

just put in package.json

"browser":{ "child_process": false }   

are you using webpack