dotnet/runtime · error · RuntimeError

Invalid OS for arm64.

Error message

Invalid OS for arm64.

What it means

Raised by determine_benchmark_machine in superpmi_aspnet.py when arch=='arm64' and host_os != 'linux'. Only an arm Linux crank machine (aspnet-citrine-arm) is provisioned.

Source

Thrown at src/coreclr/scripts/superpmi_aspnet.py:111

        coreclr_args (CoreclrArguments): parsed args

    Return:
        (str) : name of the benchmnark machine
    """

    if coreclr_args.arch == "x64":
        if coreclr_args.host_os == "windows":
            return "aspnet-perf-win"
#            return "aspnet-citrine-win"
        elif coreclr_args.host_os == "linux":
            return "aspnet-perf-lin"
        else:
            raise RuntimeError("Invalid OS for x64.")
    elif coreclr_args.arch == "arm64":
        if coreclr_args.host_os == "linux":
            return "aspnet-citrine-arm"
        else:
            raise RuntimeError("Invalid OS for arm64.")
    else:
        raise RuntimeError("Invalid arch.")

def build_and_run(coreclr_args):
    """Run perf scenarios under crank and collect data with SPMI"

    Args:
        coreclr_args (CoreClrArguments): Arguments use to drive
        output_mch_name (string): Name of output mch file name
    """
    source_directory = coreclr_args.source_directory
    target_arch = coreclr_args.arch
    target_os = coreclr_args.host_os

    checked_root = path.join(source_directory, "artifacts", "bin", "coreclr", target_os + "." + coreclr_args.arch + ".Checked")
    release_root = path.join(source_directory, "artifacts", "bin", "coreclr", target_os + "." + coreclr_args.arch + ".Release")

    # We'll use repo script to install dotnet

View on GitHub (pinned to 290d5ab72c)

Solutions

1. Use the supported combo: --arch arm64 --host_os linux.
2. If you need arm64 perf on another OS, route to a different scenario/machine pool.
3. Fix the YAML matrix entry.

Example fix

// before
# --arch arm64 --host_os windows -> raises [189]
// after
--arch arm64 --host_os linux

if coreclr_args.arch == 'arm64' and coreclr_args.host_os != 'linux':
    raise SystemExit(f'arm64 benchmarks only support linux, got {coreclr_args.host_os}')

def arm64_os_supported(arch: str, host_os: str) -> bool:
    return arch != 'arm64' or host_os == 'linux'

try:
    determine_benchmark_machine(coreclr_args)
except RuntimeError as e:
    if 'Invalid OS for arm64' in str(e):
        raise SystemExit('set --host_os linux for arm64 benchmarks')

When it happens

Trigger: coreclr_args.arch=='arm64' with host_os in {'windows','osx',...}.

Common situations: Windows/arm64 or macOS/arm64 selected in the pipeline; Architecture=arm64 but TargetOS unset/defaulted to windows.

Related errors

• Invalid OS for x64.
• Invalid arch.
• Unknown OS.
• Pass only one tiering option.
• Unrecognized asset behavior:${asset.behavior}, for asset ${a

AI-assisted analysis of dotnet/runtime@290d5ab72c (2026-08-06). Data as JSON: /api/errors/413322d8f9e36d05. Report an issue: GitHub.