This is a common problem, you can use scons -c to clear the previous cache file cconfig.h, and then execute the scons command.
If the problem is not resolved, you can check the version number of the gcc toolchain, which needs to be greater than 10. You can download Arm ToolChains 10-2020-q4 from here.
Good idea, looking forward to your finished product
This problem has been fixed. https://github.com/RT-Thread/rt-thread/pull/4512.
After merge, update the code locally.
There are still some problems:
Can someone help me solve it together?
I have added the code of Raspberry Pi PICO to the RT-thread:https://github.com/Guozhanxin/rt-thread/tree/raspberry-pico/bsp/raspberry-pico
But currently only supports running official example.
RT-Thread is not currently supported