Adding SofaPython3 plugin on Windows

[CorentinLanguepin]

I built Sofa on Windows (I took the master branch for the Sofa sources) and I tried to add the SofaPython3 plugin. When I tried via the Plugin Manager, this warning appeared on my terminal and Sofa crashed :

[WARNING] [PythonEnvironment] No python dir found in E:/sofa/build/bin

Indeed, the plugin is in the folder : E:/sofa/build/bin/Release and with the help of Damien, we saw that the problem came from the following function in PythonEnvironment.cpp :

void PythonEnvironment::addPythonModulePathsForPluginsByName(const std::string& pluginName)
{
    std::map<std::string, Plugin>& map = PluginManager::getInstance().getPluginMap();
    for( const auto& elem : map)
    {
        Plugin p = elem.second;
        if ( p.getModuleName() == pluginName )
        {
            std::string pluginLibraryPath = elem.first;
            // moduleRoot should be 2 levels above the library (plugin_name/lib/plugin_name.so)
            std::string moduleRoot = FileSystem::getParentDirectory(FileSystem::getParentDirectory(pluginLibraryPath));
            addPythonModulePathsForPlugins(moduleRoot);
            return;
        }
    }
    msg_warning("PythonEnvironment") << pluginName << " not found in PluginManager's map.";
}

It seems logical to have this warning because the function uses twice getParentDirectory and as a consequence, from E:/sofa/build/bin/Release/SofaPython3.dll we go to E:/sofa/build/bin, where there is no python3 dir.

We changed the source code and more precisely the file PythonEnvironment.cpp by adding a third getParentDirectory. Thus the line is now :

std::string moduleRoot = FileSystem::getParentDirectory(FileSystem::getParentDirectory(FileSystem::getParentDirectory(pluginLibraryPath)));

With that in mind, we added a PYTHONPATH like this : E:/sofa/build/python3/site-packages. With those changes, it seems to work but my question is : is this an error from the source code to not be able to add the plugin from the plugin manager, or is this more a problem with CMake with a Windows distribution that put some files or folders in a place where it should not be during the compilation?