Cmake, windows. "missing and no known rule to make it"

[frankdownunder]

When executing idf.py build, I get
Running ninja in directory C:\opt\esp\esp-idf\examples\wifi\power_save\build
Executing "ninja all"...
ninja: error: 'json/CMakeFiles/json.dir/cJSON/cJSON.c.obj', needed by 'json/libjson.a', missing and no known rule to make it
ninja failed with exit code 1

I suspected the relative path name, and can confirm that manually editing the ninja file to have an absolute path name, it builds that rule OK.

What am I doing wrong?

[ESP_Angus]

Hi Frank,

That's unusual. Could you please post the full output from "idf.py reconfigure build"?

Thanks,

Angus