Local repositories break with libraries which use native C++ files

[EliteMasterEric]

hxCodec is a good demonstration of this issue.

1. Use haxelib newrepo to create a local repository.
2. Install hxCodec into that local repo and try to build a project which uses it (hxCodec has several sample projects)
3. You will receive an error that one of the included build files is missing.
4. cd out of the folder and install hxCodec there.
5. You will no longer receive the error about the missing build file.

I presume that whatever functionality is retrieving the build file is using the absolute haxelib location and not respecting the relevant local repositories.