Fans spinning to a human audible level indicates your Mac is hot and your CPU is probably working hard. I recently updated to the powerful 2018 MacBook Pro 15”, so was surprised to hear them, with little more than Docker, VS Code, and Angular’s ng serve running .

A little Googling as usual, and I found this issue. npm i fsevents, as suggested - reduced my CPU load from ~12% to ~2%, and quickly stopped the audible fan noise. This is specific to Mac, but I thought should be shared, as I was worried there was a heat issue with my Mac, or all new Macs in general.

As the user @PyroSA kindly assumes, this is due to anguarl-cli now being subscribed to File System Events, instead of directly polling files to check for changes.