ditto: can't get real path for source 'tulsi-aspects'

Hello!

I am trying to play with `xchammer`. I followed the only documentation that I found in the repo, cloned it and ran `make install`. The compilation of the project and its dependencies works as expected, but ends up failing with `ditto: can't get real path for source 'tulsi-aspects'`. You can see the last part of the log here:
```
...
Compile Swift Module 'Commandant' (9 sources)
Compile Swift Module 'AEXML' (5 sources)
Compile CYaml src/emitter.c
Compile CYaml src/api.c
Compile Swift Module 'Yams' (16 sources)
Compile Swift Module 'xcproj' (61 sources)
Archiving /Users/balestrapatrick/Downloads/xchammer-master/.build/x86_64-apple-macosx10.10/release/libTulsiGenerator.a
Compile Swift Module 'ProjectSpec' (25 sources)
Compile Swift Module 'XcodeGenKit' (8 sources)
Compile Swift Module 'XCHammer' (20 sources)
Linking ./.build/x86_64-apple-macosx10.10/release/XCHammer
# Install bundle resources
# Install Tulsi resources
# Tulsi utilizes NSBundle heavily. All assets need to exist at the root of
# this directory in order for NSBundle and Tulsi's searching logic to work
# in the context of our custom release package.
ditto: can't get real path for source 'tulsi-aspects'
make: *** [build-impl] Error 1
```

Any idea what's wrong? I have Tulsi installed, and from what I can understand the `Makefile` tries to reference `tulsi-aspects` which is unsuccessful on my machine (not sure exactly what `tulsi-aspects` is and couldn't find many information about it).

Thank you! 👍