Using ESP 32 Ardiono framework and platformio.org's library search functionality presents a vexing problem since the name HttpClient.h is duplicated in the ESP32 Arduino framework.

If you try to use both, the ArduinoHttpClient overrides the platform default, so it breaks anything else that uses HttpClient.h. Note that despite the cases of the classes being different, at least on windows the case of the filename does not matter, so the wrong file is included in any module that references it.

I was finally able to workarourd this my renaming the HttpClient.h -> MCQN_HttpClient.h . Your method may vary, but since this framework and platformio are very popular, this library should really not duplicate the header filename.