Add test for dotnet incompatible projects

csharp/ql/integration-tests/all-platforms/diag_dotnet_incompatible/diagnostics.expected

@@ -0,0 +1,32 @@
+{
+  "attributes": {},
+  "helpLinks": [],
+  "internal": false,
+  "location": {},
+  "markdownMessage": "CodeQL found some projects which cannot be built with .NET Core:\n- `test.csproj`",
+  "severity": "warning",
+  "source": {
+    "extractorName": "csharp",
+    "id": "csharp/autobuilder/dotnet-incompatible-projects",
+    "name": "Some projects are incompatible with .NET Core"
+  },
+  "visibility": {
+    "statusPage": true
+  }
+}
+{
+  "attributes": {},
+  "helpLinks": [],
+  "internal": false,
+  "location": {},
+  "markdownMessage": "CodeQL was unable to build the following projects using MSBuild:\n- `test.csproj`\nSet up a [manual build command](https://docs.github.com/en/code-security/code-scanning/automatically-scanning-your-code-for-vulnerabilities-and-errors/configuring-the-codeql-workflow-for-compiled-languages).",
+  "severity": "error",
+  "source": {
+    "extractorName": "csharp",
+    "id": "csharp/autobuilder/msbuild-build-failure",
+    "name": "Some projects or solutions failed to build using MSBuild"
+  },
+  "visibility": {
+    "statusPage": true
+  }
+}

csharp/ql/integration-tests/all-platforms/diag_dotnet_incompatible/test.csproj

@@ -0,0 +1,66 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
+  <PropertyGroup>
+    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
+    <ProjectGuid>{F70CE6B6-1735-4AD2-B1EB-B91FCD1012D1}</ProjectGuid>
+    <OutputType>Library</OutputType>
+    <AppDesignerFolder>Properties</AppDesignerFolder>
+    <RootNamespace>Example</RootNamespace>
+    <AssemblyName>Example</AssemblyName>
+    <TargetFrameworkVersion>v4.0</TargetFrameworkVersion>
+    <FileAlignment>512</FileAlignment>
+    <TargetFrameworkProfile />
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
+    <DebugSymbols>true</DebugSymbols>
+    <DebugType>full</DebugType>
+    <Optimize>false</Optimize>
+    <OutputPath>bin\Debug\</OutputPath>
+    <DefineConstants>DEBUG;TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
+    <DebugType>pdbonly</DebugType>
+    <Optimize>true</Optimize>
+    <OutputPath>bin\Release\</OutputPath>
+    <DefineConstants>TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+  </PropertyGroup>
+  <PropertyGroup />
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Debug|x86'">
+    <DebugSymbols>true</DebugSymbols>
+    <OutputPath>bin\x86\Debug\</OutputPath>
+    <DefineConstants>DEBUG;TRACE</DefineConstants>
+    <DebugType>full</DebugType>
+    <PlatformTarget>x86</PlatformTarget>
+    <ErrorReport>prompt</ErrorReport>
+    <CodeAnalysisRuleSet>MinimumRecommendedRules.ruleset</CodeAnalysisRuleSet>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Release|x86'">
+    <OutputPath>bin\x86\Release\</OutputPath>
+    <DefineConstants>TRACE</DefineConstants>
+    <Optimize>true</Optimize>
+    <DebugType>pdbonly</DebugType>
+    <PlatformTarget>x86</PlatformTarget>
+    <ErrorReport>prompt</ErrorReport>
+    <CodeAnalysisRuleSet>MinimumRecommendedRules.ruleset</CodeAnalysisRuleSet>
+  </PropertyGroup>
+  <ItemGroup>
+    <Reference Include="System" />
+  </ItemGroup>
+  <ItemGroup>
+    <Compile Include="Program.cs" />
+  </ItemGroup>
+  <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
+  <!-- To modify your build process, add your task inside one of the targets below and uncomment it.
+       Other similar extension points exist, see Microsoft.Common.targets.
+  <Target Name="BeforeBuild">
+  </Target>
+  <Target Name="AfterBuild">
+  </Target>
+  -->
+</Project>

csharp/ql/integration-tests/all-platforms/diag_dotnet_incompatible/test.py

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+from create_database_utils import *
+from diagnostics_test_utils import *
+
+run_codeql_database_create([], db=None, lang="csharp", runFunction=runUnsuccessfully)
+check_diagnostics()