Ok, today I have time to investigate this problem a little further. What I got so far: The binary version of clang-tidy.exe (resides in .platformio\packages\tool-clangtidy) is 12.0.1. The corresponding documentation can be found here: Clang-Tidy — Extra Clang Tools 12 documentation
There is nothing telling us about a config-file argument. But when I run
it says that there is a possibility to use
Specify the path of .clang-tidy or custom config file: e.g. --config-file=/some/path/myTidyConfigFile This option internally works exactly the same way as --config option after reading specified config file. Use either --config-file or --config, not both.
But I am not yet able to use it.