fatal error: ESP8266WiFi.h: No such file or directory I used platformio IDE
I did &quot;platformio lib install 1101&quot;
(http://platformio.org/lib/show/1101/ESP8266wifi),
I installed this: http://platformio.org/lib/show/549/WebSockets (follow instructions)
I did similar things to other libraries.
When I click the platformio:build button, it still complains:

fatal error: ESP8266WiFi.h: No such file or directory fatal error:
ESP8266WiFiMulti.h: No such file or directory fatal error:
ESP8266Webserver.h: No such file or directory
Have you overridden lib_dir in platformio.ini? If yes, please remove it.