error: This is probably not a problem with npm. There is likely additional logging output above

Delete your package-lock.json file and node_modules folder. Then do npm cache clean

npm cache clean --force

do npm install

again and run

Finally, I found a solution to this problem without reinstalling npm and I'm posting it because in future it will help someone, Most of the time this error occurs javascript heap went out of the memory. As the error says itself this is not a problem with npm. Only we have to do is

instead of,

npm  run build -prod

extend the javascript memory by following,

node --max_old_space_size=4096 node_modules/@angular/cli/bin/ng build --prod

I'm on Ubuntu 18.04. I fixed this problem by increasing the inotify max_user_watches using this command:

echo 65536 | sudo tee -a /proc/sys/fs/inotify/max_user_watches