Just for clarifying:

>
> 2. is a bit hacky: My definition of workspace folder is:
> - there is a CMakeLists.txt

The workspace folder does not contain a CMakeLists.txt. The CMakeLists.txt is in the source folder of the workspace.

> - that is a symlink

The file may not be a symlink, i.e. on Windows it is not.

> - to the main cmake in /opt/ros

If it is a symlink it may not point to something in /opt/ros. Catkin could be build from source, potentially is not even installed but only in a devel space or installed to a different location.

Since there is no heuristic which can reliable detect a workspace folder we proposed the marker file.

- Dirk