Xcode 8 very slow Swift compiling

Question

Ever since Swift 3 and Xcode 8 my project compiles quite slowly. Every time I add so much as an empty line to a file, recompiling takes a full minute. When I check the outpu

Answer 1

This is an issue with Xcode 8 where it does not perform incremental builds correctly. If you edit a single swift file it should compile only that file only. This has already been raised here: Xcode 8 does full project rebuild

The 4 files at a time build sounds like Xcode is performing a full rebuild of the project which should not happen again if you only modified a single line in one file.