Using library with Longan Nano: missing file "rttgui.h

[RudolfAtHome]

Compiling example "Blinkk.ino" from library examples produces the Error:

ResolveLibrary(rttgui.h)
d:\Arduino\libraries\Arduino_RT-Thread-master\src\components\arduino\drv_spi_st7735.cpp:16:11: fatal error: rttgui.h: No such file or directory
   16 | # include <rttgui.h>
      |           ^~~~~~~~~~
compilation terminated.

This libraty is included when "# define CONFIG_USING_GUI               (1)"  is given. this is set in "rtconfig.h" 
**There is no file named "rttgui.h" in the whole library!**

**Library (please complete the following information):**
 - Version 1.0.0
 - Config Windows 10, Arduino IDE 2.0.0-rc8, gdvduino V0.1.1

**Additional context**
Add any other context about the problem here.

[onelife]

Hi @RudolfAtHome, The CONFIG_USING_GUI flag has to work together with the RTT-GUI library. Please install RTT-GUI and try.