add_custom_command(OUTPUT ...) doesn't work in C# projects
I've been playing with the new (and very welcome) C# support, but I've found that add_custom_command doesn't work for C# projects. I want to use this to generate source files for version and build date information, like I do for my C++ projects. The <CustomBuild> entries for the add_custom_command are created in the csproj file, but they never run. As a consequence, the C# build fails with an error that the .cs file is not found.
See the attached zip file for a minimal example, which demonstrates that the identical approach works for C++, but not in C#.
Note that because of this, the custom CMakeLists.txt rule ("Building Custom Rule C:/.../src/CMakeLists.txt") doesn't appear to run either.