Weird issues on Travis Xcode10.1 #2751
There is some weird issue that appears only on Travis, when using the Xcode10.1 image.
After fixing #2749 the Haskell builds might work on macOS 10.14, which would probably fix the issues.
The weird issues also occur, if Haskell is disabled. However, if all the Haskell stuff gets an update, it might be possible to build the Haskell plugins with macOS 10.14. Under macOS 10.14 the issues don't seem to exist.