Concurrent Carthage is a faster Carthage which utilizes multiple cores to build frameworks.
ruby main.rb
Concurrent Carthage
carthage build --platform iOS --platform macOS 231.98s user 100.72s system 455% cpu 1:13.01 total
Original Carthage
carthage build --platform iOS --platform macOS 125.28s user 54.45s system 86% cpu 3:26.99 total
If your frameworks have too many nested dependencies, Concurrent Carthage can't speed it up very much.