Msbuild fails in custom derivation

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1

https://github.com/NixOS/nixpkgs/issues/211666
I’m having the same issue trying to package Ultimate Doom Builder, but i’m unable to build manually. Using the same nix expression as Zaechus and my error output is slightly different:

msbuild /nologo /verbosity:minimal -p:Configuration=Release BuilderMono.sln
Fontconfig error: Cannot load default config file: No such file: (null)
Fontconfig error: No writable cache directories
Fontconfig error: No writable cache directories
Fontconfig error: No writable cache directories
Fontconfig error: No writable cache directories
libpng warning: Interlace handling should be turned on when using png_read_image
libpng warning: Interlace handling should be turned on when using png_read_image
libpng warning: Interlace handling should be turned on when using png_read_image
libpng warning: Interlace handling should be turned on when using png_read_image
libpng warning: Interlace handling should be turned on when using png_read_image
CSC : error CS1504: Source file '/build/source/Source/Core/Windows/ResourceOptionsForm.cs' could not be opened -- GetCPInfoExW assembly:<unknown assembly> type:<unknown type> member:(null) [/build/source/Source/Core/BuilderMono.csproj]
CSC : error CS1504: Source file '/build/source/Source/Core/Geometry/Vector2D.cs' could not be opened -- GetCPInfoExW assembly:<unknown assembly> type:<unknown type> member:(null) [/build/source/Source/Core/BuilderMono.csproj]
CSC : error CS1504: Source file '/build/source/Source/Core/Controls/MultiSelectTreeview.cs' could not be opened -- GetCPInfoExW assembly:<unknown assembly> type:<unknown type> member:(null) [/build/source/Source/Core/BuilderMono.csproj]
make: *** [Makefile:14: builder] Error 1
2

It ended up being as simple as setting a compile option. you can read the expression i sent in the issue i linked in OP for a possible solution