c_cpp_properties.json file ${IDF_PATH} fails to resolve.

[davidmoshal]

Given a library include statement with 'squiggly' lines. When the lightbulb icon is selected and the absolute path is included in c_cpp_properties.json file, the squiggly lines disappear.

However, if the path is substituted, then the squiggly lines return.

ie: this works: "/home/davem/esp/esp-idf/components/soc/soc/include" but this fails: "${IDF_PATH}/components/soc/soc/include"

curiously, the environment variable is correct:

echo ${IDF_PATH}
/home/davem/esp/esp-idf