Nop, it's not supported 😞. For most of the features, the extension acts as a wrapper around the ceedling CLI. But to get some of the info, the project.yml file is parsed and none of the option_paths is followed. To be honest I didn't even knew this feature existed 😅.

Ok thank you very much for your answer.
Hope this will be considered in the future as it is very practical to test multiple configuration of the same generic code (eg: subsystem) or Hardware Abstraction Layer based on preprocessing (eg: HAL CHIP MODEL, motor...).
Regards

This feature would be very appreciated, I have just discovered the extension but my projects are based on a project.yml and project_specific.yml file.

Calling ceedling summary report :

ERROR: Config filepath [:tools][:test_compiler][:executable]['gcc.exe'] does not exist in system search paths.
ERROR: Config filepath [:tools][:test_dependencies_generator][:executable]['gcc.exe'] does not exist in system search paths.
ERROR: Config filepath [:tools][:test_file_preprocessor][:executable]['gcc.exe'] does not exist in system search paths.
ERROR: Config filepath [:tools][:test_file_preprocessor_directives][:executable]['gcc.exe'] does not exist in system search paths.
ERROR: Config filepath [:tools][:test_includes_preprocessor][:executable]['gcc.exe'] does not exist in system search paths.
ERROR: Config filepath [:tools][:test_linker][:executable]['gcc.exe'] does not exist in system search paths.

but calling ceedling project:project_specific.yml summary is working fine as compiler path are specified in specific.yml

Just modified adapter.js to add project:project_specific.yml to every ceedling cmd

    getCeedlingCommand(args) {
        const line = `ceedling project:project_specific.yml ${args.join(" ")}`;
        return line;
    }

I don't know how VS extension works but I will try to propose a PR to add a setting for this.

Just wanted to chime in that I would love to see support for the "options" feature as well. I usually have multiple HALs for my project to support different hardware builds, options are great for appending the paths of a specific HAL for inclusion in a build. I know that the options feature supports an "export" function (e.g. options:export[filename]) where ceedling will spit out the result of the yaml merger, but it looks like it only works for the "tools" section. That seems like it might be an oversight in the ceedling project.