I have a package using setup.py.  I want the package to include some data files, which are located in my source directory.  Building my package in my 3.7.0 environment includes the data files as expected.  Building the same exact package in my 3.7.1 environment does NOT include the data files.

Attached are two logs demonstrating the `pip install` output.  Both were produced with this command: `pip uninstall 0x-json-schemas --yes >pip.log && pip install .[dev] --verbose --verbose --verbose >> pip.log`

Also attached is my setup.py script.

Also worth noting is that the directory that contains my data files (src/zero_ex/json_schemas/schemas) is a symlink, which I've verified is resolving properly in both environments.  And, when I replace the symlink with a real folder, containing the same files, then everything works as expected.  So I surmise that the following of symlinks is what's broken here.