Hi,
When I try to build the dev mode assets for Jupyterlab, i.e., when I run the command jlpm --verbose run build, I face this error. I have tried everything I can to resolve this but I am unable to get through this.
Tried uninstalling and reinstalling Nodejs and npm as well. But no luck. Need help
jlpm run integrity && jlpm run build:vega && jlpm run build:packages && cd dev_mode && jlpm run build
node buildutils/lib/ensure-repo.js
internal/modules/cjs/loader.js:638
throw err;
^
Error: Cannot find module ‘fs-extra’
at Function.Module._resolveFilename (internal/modules/cjs/loader.js:636:15)
at Function.Module._load (internal/modules/cjs/loader.js:562:25)
at Module.require (internal/modules/cjs/loader.js:690:17)
at require (internal/modules/cjs/helpers.js:25:18)
at Object. (/Users/c053794/workingdir/jupyterlab/buildutils/lib/utils.js:5:12)
Can you give step-by-step instructions to reproduce your setup in a clean environment? Please include versions of jupyterlab, node, etc.
For example, if you install things through conda, you can do conda create -n myenvironment jupyterlab=2 nodejs=13
I was able to find a solution and was able to fix the errors. Thank you for you reply 
Do you mind sharing what you did, in case others see similar issues and are looking for help?
So, when I was trying to run ‘jlpm --verbose run build’ command, I received a lot of errors like:
Cannot find module 'glob'
Error: Cannot find module 'glob'
Cannot find module 'fs-extra'
Error: Cannot find module 'fs-extra'
Cannot find module 'sort-package-json'
Error: Cannot find module 'sort-package-json'
And couple more. Initially what I did, I tried installing each of those modules using the below commands:
sudo npm install --save glob
sudo npm install --save fs-extra
sudo npm install --save dependency-graph
sudo npm install --save sort-package-json
sudo npm install --save @phosphor/coreutils
sudo npm install --save prettier
sudo npm install --save typescript
But everytime, I resolve one issue, a new package issue was found. So, I wanted to re-install all the missing packages. For that, I had to uninstall nodejs and npm and once I uninstalled and deleted all the files from my drives:
brew uninstall node
brew unlink node
brew unlink npm
brew unlink node_modules
rm -rf /usr/local/lib/node_modules
sudo rm -rf /usr/local/{lib/node{,/.npm,_modules},bin,share/man}/{npm*,node*,man1/node*}
sudo rm -rf /usr/local/bin/npm /usr/local/share/man/man1/node* /usr/local/lib/dtrace/node.d ~/.npm ~/.node-gyp
I ran these commands:
brew install node
npm install yarn -g
npm install -g typescript
npm install
yarn install
That fixed all the issues