What causes "Runtime moniker {runtimeMoniker} is not supported" in dotnet/BenchmarkDotNet?

Upgrade BenchmarkDotNet.Diagnostics.dotMemory to a version whose IsSupported switch covers your target framework moniker.

dotnet/BenchmarkDotNet · error · ArgumentOutOfRangeException

Runtime moniker {runtimeMoniker} is not supported

Error message

Runtime moniker {runtimeMoniker} is not supported

What it means

DotMemoryDiagnoser.IsSupported exhaustively lists every RuntimeMoniker in its switch and throws ArgumentOutOfRangeException on the default branch. The message is a string template ('$"...{runtimeMoniker}...") that will not interpolate in an Exception.Message unless formatted, but the intent is: the diagnoser encountered a runtime moniker it has not been updated to recognize.

Source

Thrown at src/BenchmarkDotNet.Diagnostics.dotMemory/DotMemoryDiagnoser.cs:127

            case RuntimeMoniker.MonoAOTLLVMNet90:
            case RuntimeMoniker.MonoAOTLLVMNet10_0:
            case RuntimeMoniker.MonoAOTLLVMNet11_0:
            case RuntimeMoniker.Mono60:
            case RuntimeMoniker.Mono70:
            case RuntimeMoniker.Mono80:
            case RuntimeMoniker.Mono90:
            case RuntimeMoniker.Mono10_0:
            case RuntimeMoniker.Mono11_0:
                return false;
            case RuntimeMoniker.NetCoreApp20:
            case RuntimeMoniker.NetCoreApp21:
            case RuntimeMoniker.NetCoreApp22:
                return OsDetector.IsWindows();
            case RuntimeMoniker.NetCoreApp30:
            case RuntimeMoniker.NetCoreApp31:
                return OsDetector.IsWindows() || OsDetector.IsLinux();
            default:
                throw new ArgumentOutOfRangeException(nameof(runtimeMoniker), runtimeMoniker, $"Runtime moniker {runtimeMoniker} is not supported");
        }
    }
}

View on GitHub (pinned to b515068b61)

Solutions

Upgrade BenchmarkDotNet.Diagnostics.dotMemory to a version whose IsSupported switch covers your target framework moniker.
If forking/patching, add the missing case returning the desired bool.
Downgrade or change the Job's runtime to a supported moniker.

Defensive patterns

Strategy: validation

Validate before calling

// Before assigning a Job runtime, gate on a supported moniker set, or upgrade BDN:
static readonly HashSet<RuntimeMoniker> DotMemorySupported = new()
{ RuntimeMoniker.Net80, RuntimeMoniker.Net90, RuntimeMoniker.Net60 /* ...per IsSupported */ };
if (!DotMemorySupported.Contains(job.Runtime.Moniker))
    throw new NotSupportedException($"dotMemory diagnoser does not support {job.Runtime.Moniker}; upgrade BDN.");

Prevention

Use a BenchmarkDotNet.Diagnostics.dotMemory build whose IsSupported covers your target moniker.
Avoid preview SDKs that map to monikers not yet enumerated.
Add the missing case in IsSupported when patching BDN.

When it happens

Trigger: A new .NET version ships a RuntimeMoniker value that this BDN build's IsSupported switch has not enumerated yet; or a custom/derived RuntimeMoniker. The throw is reached only for genuinely unknown values - all currently known monikers return true or false.

Common situations: Running a newer BenchmarkDotNet engine that emits a moniker newer than the dotMemory diagnoser build recognizes; using a preview SDK that maps to a moniker not yet in the switch.

Related errors

AI-assisted analysis of dotnet/BenchmarkDotNet@b515068b61 (2026-08-13). Data as JSON: /api/errors/87d3ef12019ae23f. Report an issue: GitHub.