For some reasons, my testing project is considered non-user code according to the debug Modules. It's also optimized when it's built for Debug. As a result, the symbols are not loaded and all break points in the testing project are skipped. I have tried the solutions sHow do I remedy "The breakpoint will not currently be hit. No symbols have been loaded for this document." warning?:
In case this is helpful, I found that in the .csproj file there are some conditional settings that reverse the settings from the GUI. How these extra settings get there remains a puzzle, but the lesson maybe that the GUI cannot fully control the settings and the .csproj file can override it.
<PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|AnyCPU'">
<Optimize>True</Optimize>
<DebugType>portable</DebugType>
</PropertyGroup>
<PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|AnyCPU'">
<Optimize>False</Optimize>
<DebugType>portable</DebugType>
</PropertyGroup>