USB installer building error "Segmentation fault"

Hiya.

I'm following the updated vanilla guide and I'm stuck at USB build.

I'm trying to build on a macpro 3.1. I'm using a Mojave installer that I downloaded with dosdude's patcher. The USB is a Corsair Survivor 16gb, formatted with the vanilla's terminal command.

The error is "Segmentation fault". It is spit out immediately. It's a common error for other things, so it's difficult to Google.

Anyone have any experience with this error or an alternative for building a vanilla USB installer?