test/dotnet: add cross-target test

pkgs/test/dotnet/cross-target/default.nix

@@ -0,0 +1,47 @@
+{
+  lib,
+  dotnet-sdk,
+  dotnetCorePackages,
+  stdenv,
+}:
+
+let
+  sdks = {
+    inherit (dotnetCorePackages)
+      sdk_10_0
+      sdk_9_0
+      sdk_8_0
+      ;
+  };
+
+  mkTest =
+    dotnet-sdk_target:
+
+    stdenv.mkDerivation {
+      name = "dotnet-cross-target-${dotnet-sdk_target.version}-test";
+
+      nativeBuildInputs = [
+        (dotnetCorePackages.combinePackages [
+          dotnet-sdk
+          dotnet-sdk_target
+        ])
+      ]
+      ++ dotnet-sdk_target.packages;
+
+      unpackPhase = ''
+        runHook preUnpack
+        mkdir test
+        cd test
+        ${dotnet-sdk_target}/bin/dotnet new console --no-restore
+        runHook postUnpack
+      '';
+
+      installPhase = ''
+        runHook preInstall
+        dotnet run > $out
+        runHook postInstall
+      '';
+    };
+
+in
+lib.recurseIntoAttrs (lib.mapAttrs (_: mkTest) sdks)

pkgs/test/dotnet/default.nix

@@ -6,4 +6,5 @@
   structured-attrs = lib.recurseIntoAttrs (callPackage ./structured-attrs { });
   final-attrs = lib.recurseIntoAttrs (callPackage ./final-attrs { });
   nuget-deps = lib.recurseIntoAttrs (callPackage ./nuget-deps { });
+  cross-target = callPackage ./cross-target { };
 }