There are still many Arduino board variants with a dash in the name. For example, "ttgo-lora32-v1" or "lolin32-lite".

In CMakeLists.txt, this variant name is capitalized and then a macro -DARDUINO_${idf_target_caps}_DEV is defined. However, the C preprocessor does not like macro names with dashes. According to the documentation : "An identifier is the same as an identifier in C: any sequence of letters, digits, or underscores, which begins with a letter or underscore."

So, my suggestion is to replace the dashed (-) with an underscore (_) in the macro definition. This could be implemented in the CMakeLists.txt file as :

string(REPLACE "-" "_" idf_target_for_macro "${idf_target_caps}")
target_compile_options(${COMPONENT_TARGET} PUBLIC
    ...
    -DARDUINO_${idf_target_for_macro}_DEV
    ...

I already made some tests, and it seems to work. Does someone see a problem with this idea? If no, I would be happy to propose a pull request with this change.

Note that this problem was also addresses in PlatformIO : platformio/platform-espressif32#81