Some more information in case someone is searching for segmentation fault on a build using Parcel v2.
I was also having this issue and tried upgrading to Sharp 0.29.0. (Sharp is used by the Parcel image transformer @parcel/transformer-image). That didn’t work. I removed all of the instances where I was resizing and converting to webP and my build started working. I added back just one resize and segmentation fault happened again.
One thing that I’m curious about though is I tried using macOS’s time to profile the memory usage and it showed under 800MB. This is well below the 3GB Netlify claims they use.
If you’re interested, here’s the command I used: /usr/bin/time -l npm run build