DotNET

.NET packages can be built with buildDotnetModule

More information about buildDotnetModule can be found in the nixpkgs manual Example build file:

{ fetchFromGitHub
, buildDotnetModule
}:

buildDotnetModule rec {
  pname = "some_program";
  version = "some_version";

  src = fetchFromGitHub {
    owner = "some_owner";
    repo = pname;
    rev = "v${version}";
    sha256 = "";
  };

  projectFile = "SomeProject/SomeProject.csproj"

  meta = with lib; {
    homepage = "some_homepage";
    description = "some_description";
    license = licenses.mit;
  };
}

Note that the above package will not build the first time. After adding the above definition to `all-packages.nix`, you can run the package-specific `fetch-deps` script, which will generate a file containing all the nuget dependencies of the package. Build the script with nix-build -A some-package.fetch-deps, copy that generated file (the location will be printed by the script) and set the nugetDeps</cude> attribute in buildDotnetModule to point to that generated file (ie. nugetDeps = ./deps.nix).

After that the package will build normally. Remember to re-run fetch-deps every time the package is updated.

Building non-.NET Core packages

Keep in mind that building non-.NET Core projects (ie. projects that don't build using the dotnet CLI tool) is not well supported. For those projects, you have to work on a custom derivation or override the buildDotnetModule build steps.

.NET location: Not found

If running a .NET-build executable you get the above error, make sure the DOTNET_ROOT environment variable is set:

environment.sessionVariables = {
  DOTNET_ROOT = "${pkgs.dotnet-sdk}";
};

See : https://learn.microsoft.com/en-us/dotnet/core/tools/dotnet-environment-variables#net-sdk-and-cli-environment-variables

TargetFramework value was not recognized

error NETSDK1013: The TargetFramework value 'net6.0-windows' was not recognized. It may be misspelled. If not, then the TargetFrameworkIdentifier and/or TargetFrameworkVersion properties must be specified explicitly.

Wontfix: The project will build only on Windows.

NativeAOT

This is relevant for NixOS only.

nix-ld is needed:

{
  programs.nix-ld.enable = true;
}

Now we will need a bunch of native dependencies. Here's an example of a shell:

with import <nixpkgs> {};
pkgs.mkShell rec {

  dotnetPkg = 
    (with dotnetCorePackages; combinePackages [
      sdk_7_0
    ]);

  deps = [
    zlib
    zlib.dev
    openssl
    dotnetPkg
  ];

  NIX_LD_LIBRARY_PATH = lib.makeLibraryPath ([
    stdenv.cc.cc
  ] ++ deps);
  NIX_LD = "${pkgs.stdenv.cc.libc_bin}/bin/ld.so";
  nativeBuildInputs = [ 
  ] ++ deps;

  shellHook = ''
    DOTNET_ROOT="${dotnetPkg}";
  '';
}

Global Tools

There is currently no mechanism to install them globally, and regular (mutable) installation does not work.

Here is a proof of concept of how .NET tools could be used declaratively.

Here's an example of using that package:

packages =                                                        
  let dotnetPkg =                                                 
    (with dotnetCorePackages; combinePackages [                   
      sdk_7_0                                                     
      sdk_6_0                                                     
    ]);                                                           
    dotnetTools = (callPackage ./dotnet-tool.nix {});     # dotnet-tool.nix is the file from the link above
  in [                                                            
    vim                                                           
    firefox                                                       
    dotnetPkg                                                     
    dotnetTools.combineTools dotnetPkg (with dotnetTools.tools; [ 
                          #  ^^^^^^^^^ here we specify the dotnet package 
                          # that will be invoked for this tool
                          # Ideally, something like dotnetPkg.withTools
                          # should be there

      fsautocomplete                                      # these are tools from dotnetTools.tools;        
      csharp-ls                                           # if a package is missing, it can be declared
      dotnet-repl                                         # manually, see the sources of dotnet-tools.nix
    ])                                                            
  ];

See also

• dotnet in the nixpkgs manual
• buildDotnetModule references in nixpkgs
• The journey of packaging a .NET app on Nix
• https://en.wikipedia.org/wiki/.NET_Framework - The old, windows-only version of .NET. Newer versions (ie. .NET Core) are multiplatform.
  • https://en.wikipedia.org/wiki/Mono_(software) is the deprecated open source implementation of the DotNET compiler and runtime. It has transformed into .NET Core.
• https://learn.microsoft.com/en-us/dotnet/core/introduction
  • https://en.wikipedia.org/wiki/List_of_CLI_languages: C#, F#, Visual Basic, ...