trying to work locally with this (not adding to the global library, but using it locally). I found that arduino ide does not recognize .inc files. However, if I copy .inc files to the temp sketch folder (after opening the ide) *C:\Users\admin\AppData\Local\Temp\arduino_build_692308\sketch* it verifies perfectly.
The IDE only recognizes certain extensions for files to be included. .inc is not on the list.