Ninja: Mixing Swift in ObjC: "fatal error: 'ObjcSwiftNinja-Swift.h' file not found"
While it works fine with Xcode, I seem unable to use Ninja to build a mixed ObjC+Swift project. I get:
/Users/User/Developer/ObjcSwiftNinja/MyObjC.m:2:9: fatal error: 'ObjcSwiftNinja-Swift.h' file not found
#import "ObjcSwiftNinja-Swift.h"
^~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.
Minimal sample project: https://github.com/Coeur/ObjcSwiftNinja
The CMakeList.txt is as minimal as possible to highlight the issue: https://github.com/Coeur/ObjcSwiftNinja/blob/97d926d454a8210731b42ddcc92c3a7fbc72ff9a/CMakeLists.txt
The README gives what works and what fails. Succeeds:
cmake -B build -G Xcode
xcodebuild -project build/ObjcSwiftNinja.xcodeproj -target ObjcSwiftNinja-app
Fails:
cmake -B build -G Ninja
ninja -C build ObjcSwiftNinja-app
I've opened an issue at ninja, but they closed it and said it was a cmake issue: https://github.com/ninja-build/ninja/issues/2261