Besides MSBuild binaries, to get msbuild.exe work also needs additional dependencies (Roslyn compilers, NuGet, etc.) as the beginning of the walkthrough introduces the "bootstrap" directory. The MSBuild solution at the repository root couldn't work by itself.

And the wiki introduces debugging MSBuild by attaching the debugger through setting the environment variableMSBUILDDEBUGONSTART. After running build.cmd, you need to open the MSBuild solution, then from a command prompt set the environment variable and build a project/solution usingartifacts\bin\bootstrap\net472\MSBuild\Current\Bin\MSBuild.exe. A pop-up window will appear to let you choose the debugger. The opened MSBuild solution is the right one.

Thank you, I had not understood that I couldn't just launch the debugger in VS pressing F5, targeting the msbuild project. I needed to run the executable in command line and then attach the debugger. You made that clear to me, thank you. I have made some progress, I can attach VS now.

However, I'm unable to successfully build any solution. I tried different solution, and this is the error I get with a very simple one :

& ".\artifacts\bin\bootstrap\net472\MSBuild\Current\Bin\MSBuild.exe" "C:.........sln"

Unhandled Exception: System.IO.FileNotFoundException: Could not load file or assembly 'System.Threading.Tasks.Dataflow, Version=8.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'
or one of its dependencies. The system cannot find the file specified.
at Microsoft.Build.Execution.BuildManager.Dispose(Boolean disposing)
at Microsoft.Build.Execution.BuildManager.Dispose() in C:\TFS\P\eturgeon123\MSBuild\src\Build\BackEnd\BuildManager\BuildManager.cs:line 1178
at Microsoft.Build.CommandLine.MSBuildApp.BuildProject(String projectFile, String[] targets, String toolsVersion, Dictionary2 globalProperties, Dictionary2 restoreProperties,
ILogger[] loggers, LoggerVerbosity verbosity, DistributedLoggerRecord[] distributedLoggerRecords, Boolean needToValidateProject, String schemaFile, Int32 cpuCount, Boolean enableNodeReuse,
TextWriter preprocessWriter, TextWriter targetsWriter, Boolean detailedSummary, ISet1 warningsAsErrors, ISet1 warningsNotAsErrors, ISet`1 warningsAsMessages, Boolean enableRestore,
ProfilerLogger profilerLogger, Boolean enableProfiler, Boolean interactive, ProjectIsolationMode isolateProjects, GraphBuildOptions graphBuildOptions, Boolean lowPriority, Boolean
question, Boolean isBuildCheckEnabled, String[] inputResultsCaches, String outputResultsCache, Boolean saveProjectResult, BuildResult& result, Boolean reportFileAccesses, String
commandLine) in C:\TFS\P\user\MSBuild\src\MSBuild\XMake.cs:line 1694
at Microsoft.Build.CommandLine.MSBuildApp.Execute(String commandLine) in C:\TFS\P\user\MSBuild\src\MSBuild\XMake.cs:line 1045
at Microsoft.Build.CommandLine.MSBuildApp.Main() in C:\TFS\P\user\MSBuild\src\MSBuild\XMake.cs:line 276

Of course, this solution does build if I do it from visual studio.

I don't hit this error. What's the Visual Studio version you use? It's probably not compatible with the latest code in main branch of MSBuild. The "bootstrap" directory acquires the additional dependencies from local installed Visual Studio.

The latest version, 17.11.4.

the -nowarn switch seems to work. So I will have to retry the response file solution

@KalleOlaviNiemitalo

I tried it in the props file, and it does not work. I still see the MSB3277/CS0162 warnings when I build in Visual studio.
<NoWarn>NU1605;MSB3277;CS0162;CS0219</NoWarn>

Do you set a NoWarn property in the project too? If you do, it'll override what's in Directory.Build.props, unless it explicitly appends, e.g.

<PropertyGroup>    <NoWarn>$(NoWarn);CS1591</NoWarn></PropertyGroup>

I removed it from the csproj, but I still see the warnings.

Worth mentionning , I just tried the /clp:ErrorsOnly switch, which could sometimes be pleasant. But with it the build time goes from 74 seconds to 155 seconds. Which makes no sense to me .