VBCSCompilerLogger: MissingMethodException on CommandLineArguments.Errors - not wrapped in tryAccessCommandLineArgument

[HelcioMEng]

I had help of AI generated information regarding this issue and I hope information below is useful.

Summary
VBCSCompilerLogger crashes with MissingMethodException when used with MSBuild installations that ship a different version of Microsoft.CodeAnalysis than what the logger was compiled against. The CommandLineArguments.Errors property access is not wrapped in the tryAccessCommandLineArgument helper, unlike other version-sensitive property accesses in the same file.

Environment
BuildXL: 0.1.0-devBuild (built from source, C:\tools\BuildXL-src\Out\Bin\Debug\win-x64\bxl.exe)
MSBuild: 17.x (Visual Studio 2022 BuildTools / Professional)
MsBuild resolver with msBuildRuntime: "FullFramework", useManagedSharedCompilation: true
Windows build nodes
Error (Option A — standard VBCSCompilerLogger.dll from Out\Bin\Debug\win-x64\tools\vbcslogger\net472)

MSBUILD : error MSB4017: The build stopped unexpectedly because of an unexpected logger failure.
Microsoft.Build.Exceptions.InternalLoggerException: The build stopped unexpectedly because of an unexpected logger failure.
---> System.MissingMethodException: Method not found:
'System.Collections.Immutable.ImmutableArray`1<Microsoft.CodeAnalysis.Diagnostic>
Microsoft.CodeAnalysis.CommandLineArguments.get_Errors()'.
at VBCSCompilerLogger.VBCSCompilerLogger.EventSourceOnMessageRaised(Object sender, BuildMessageEventArgs e)

Error (Option B — VBCSCompilerLoggerOldCodeAnalysis.dll from Out\Objects...\testRun\Logger, renamed to VBCSCompilerLogger.dll)

MSBUILD : error MSB1028: The logger failed unexpectedly.
System.IO.FileNotFoundException: Could not load file or assembly
'Microsoft.CodeAnalysis, Version=2.10.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'
or one of its dependencies. The system cannot find the file specified.
at VBCSCompilerLogger.VBCSCompilerLogger..ctor()

Root Cause
In VBCSCompilerLogger.cs, the EventSourceOnMessageRaised method accesses parsedCommandLine.Errors directly:
IEnumerable badSwitchErrors = parsedCommandLine.Errors
.Where(diagnostic => diagnostic.Id.Contains("2007")).ToList();

This property was added in a newer version of Microsoft.CodeAnalysis. Unlike other version-sensitive accesses in the same method (e.g., AnalyzerReferences, EmbeddedFiles, AdditionalFiles, AnalyzerConfigPaths, ErrorLogOptions, etc.), the .Errors property is not wrapped in the tryAccessCommandLineArgument helper that gracefully handles MissingMethodException:

static T? tryAccessCommandLineArgument(Func accessCommandLineArgument)
{
try { return accessCommandLineArgument(); }
catch (MissingMethodException) { return default; }
}

Proposed Fix
Wrap the parsedCommandLine.Errors access in tryAccessCommandLineArgument:

ImmutableArray errors = tryAccessCommandLineArgument(() => parsedCommandLine.Errors);
IEnumerable badSwitchErrors = errors != default
? errors.Where(diagnostic => diagnostic.Id.Contains("2007")).ToList()
: Enumerable.Empty();

his is consistent with how all other version-sensitive CommandLineArguments properties are accessed in the same method.

Workaround
Set useManagedSharedCompilation: false in the resolver configuration. This disables the VBCSCompilerLogger entirely but results in slightly slower C# builds (no shared Roslyn compiler service).

Thanks a lot

[smera]

Could you provide the version of Microsoft.CodeAnalysis that you are trying to use and causes this issue?

[HelcioMEng]

Thanks for taking the time to look into this. I have build buildxl locally and have asked AI to support me to answer your question. The answer below was based on the msbuild tools installed on my vm.

Microsoft.CodeAnalysis 4.8.0.0 (Product Version: 4.8.0-7.23572.1), shipped with Visual Studio 2022 BuildTools 17.8.x.

The VBCSCompilerLogger.dll was compiled against Microsoft.CodeAnalysis 3.8.0.0. At runtime, it binds to 4.8.0.0 from the BuildTools Roslyn installation. The CommandLineArguments.Errors property is not present in either version, causing the MissingMethodException.

[smera]

The 'Errors' property on CommandLineArguments seems to be present in both 4.8.0.0 (the version you have at runtime) and the one VBCSCompiler was built against (3.8.0.0). Decompiling the assemblies I see:

// Microsoft.CodeAnalysis, Version=4.8.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35
// Microsoft.CodeAnalysis.CommandLineArguments
using System.Collections.Immutable;

/// <summary>
/// Errors while parsing the command line arguments.
/// </summary>
public ImmutableArray<Diagnostic> Errors { get; internal set; }

and

// Microsoft.CodeAnalysis, Version=3.8.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35
// Microsoft.CodeAnalysis.CommandLineArguments
using System.Collections.Immutable;

/// <summary>
/// Errors while parsing the command line arguments.
/// </summary>
public ImmutableArray<Diagnostic> Errors { get; internal set; }

this tryAccessCommandLineArgument method that can ignore missing method exceptions was meant for the case where we have to deal with code analysis packages older than 3.8.0.0 (not newer - as the general rule is that assemblies are back compat). But in your case you are using a newer assembly. Without knowing the details of your scenario, my bet is that the assembly load failure has some other root cause.

[HelcioMEng]

Can you please just give a simple information stating which version of msbuild tools should I use when building buildxl?

I graciously appreciate you and people that put effort on this, but on the other hand if I am selling something I would make sure customers would find it easy to use my product. I see great potential on this project.

[smera]

BuildXL should be able to work with an MSBuild instance with version 16.9+. Please make sure you have the latest BuildXL installed. If you hit this problem with the latest BuildXL version, please feel free to share a stack trace and we can take a look.