DotNET

.NET packages can be built with buildDotnetPackage

Example build file:

/*
some_program/default.nix
nix-build -E 'with import <nixpkgs> { }; callPackage ./default.nix { }'
*/

{ lib
, stdenv
, fetchFromGitHub
, buildDotnetPackage
, dotnetPackages
, pkg-config
}:

buildDotnetPackage rec {
  pname = "some_program";
  baseName = pname; # workaround for "called without baseName"
  version = "some_version";
  src = fetchFromGitHub {
    owner = "some_owner";
    repo = pname;
    rev = "v${version}";
    sha256 = ""; # todo
  };
  projectFile = ["path/to/some_project.csproj"];
  propagatedBuildInputs = [
  ];
  buildInputs = [
    # unit tests
    dotnetPackages.NUnit
    dotnetPackages.NUnitRunners
  ];
  nativeBuildInputs = [
    pkg-config
  ];
  meta = with lib; {
    homepage = "some_homepage";
    description = "some_description";
    license = licenses.mit;
  };
}

XML namespace error

xbuild tool is deprecated and will be removed in future updates, use msbuild instead

The default XML namespace of the project must be the MSBuild XML namespace. If the project is authored in the MSBuild 2003 format, please add xmlns="http://schemas.microsoft.com/developer/msbuild/2003" to the <Project> element. If the project has been authored in the old 1.0 or 1.2 format, please convert it to MSBuild 2003 format.

Workaround: in buildPhase, replace xbuild with msbuild

{ lib
# ...
, msbuild
}:

buildDotnetPackage rec {
  # ...
  projectFile = "path/to/some_project.csproj";
  # ...
  buildInputs = [
    msbuild
  ];
  buildPhase = ''
    runHook preBuild
    msbuild /p:Configuration=Release ${projectFile}
    runHook postBuild
  '';
}

MSBuild reference: https://docs.microsoft.com/en-us/visualstudio/msbuild/msbuild-command-line-reference?view=vs-2022

.NET location: Not found

set DOTNET_ROOT Environment Variable

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

Missing NuGet packages

Example error:

error : This project references NuGet package(s) that are missing on this computer. Use NuGet Package Restore to download them. For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is ../../packages/Microsoft.Bcl.Build.1.0.21/build/Microsoft.Bcl.Build.targets.

These are upstream bugs

As workaround, patch all *.csproj files, to remove all XML tags that contain the "missing file" paths, for example

<Import Project="..\..\packages\Microsoft.Bcl.Build.1.0.21\build\Microsoft.Bcl.Build.targets" Condition="Exists('..\..\packages\Microsoft.Bcl.Build.1.0.21\build\Microsoft.Bcl.Build.targets')" />

See also https://stackoverflow.com/questions/32254439/nuget-packages-are-missing

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}";
  '';
}

See also

• dotnet in the nixpkgs manual
• nixpkgs/pkgs/top-level/dotnet-packages.nix → look for "SOURCE PACKAGES"
• buildDotnetPackage implementation
• buildDotnetPackage references in nixpkgs
• The journey of packaging a .NET app on Nix
• https://en.wikipedia.org/wiki/.NET_Framework
  • https://en.wikipedia.org/wiki/List_of_CLI_languages: C#, F#, Visual Basic, ...
  • https://en.wikipedia.org/wiki/Mono_(software) is the open source implementation of the DotNET compiler and runtime