oraios/serena · error · SolidLSPException

No supported dotnet version found. Available versions: {', '

Error message

No supported dotnet version found. Available versions: {', '.join(available_version_cmd_output)}. Supported versions: 4, 6, 7, 8, 9

What it means

Raised by get_dotnet_version when dotnet is present and reports runtimes, but none start with a supported major version (4, 6, 7, 8, 9). The message lists all detected runtime versions so you can see what is installed.

Source

Thrown at src/solidlsp/ls_utils.py:780

            if not available_version_cmd_output:
                raise SolidLSPException("dotnet not found on the system")

            # Check for supported versions in order of preference (latest first)
            for version_cmd_output in available_version_cmd_output:
                if version_cmd_output.startswith("9"):
                    return DotnetVersion.V9
                if version_cmd_output.startswith("8"):
                    return DotnetVersion.V8
                if version_cmd_output.startswith("7"):
                    return DotnetVersion.V7
                if version_cmd_output.startswith("6"):
                    return DotnetVersion.V6
                if version_cmd_output.startswith("4"):
                    return DotnetVersion.V4

            # If no supported version found, raise exception with all available versions
            raise SolidLSPException(
                f"No supported dotnet version found. Available versions: {', '.join(available_version_cmd_output)}. Supported versions: 4, 6, 7, 8, 9"
            )
        except (FileNotFoundError, subprocess.CalledProcessError):
            try:
                result = subprocess_run(["mono", "--version"], capture_output=True, check=True)
                return DotnetVersion.VMONO
            except (FileNotFoundError, subprocess.CalledProcessError):
                raise SolidLSPException("dotnet or mono not found on the system")


class SymbolUtils:
    @staticmethod
    def symbol_tree_contains_name(roots: list[UnifiedSymbolInformation], name: str) -> bool:
        """
        Check if any symbol in the tree has a name matching the given name.
        """
        for symbol in roots:
            if symbol["name"] == name:

View on GitHub (pinned to 7fcbca7e62)

Solutions

Install a supported runtime, e.g. `dotnet-runtime-8` alongside existing ones (side-by-side is safe)
If a new major (e.g. 10) is installed, additionally install a supported LTS version
Update the library to a version supporting your .NET major

Example fix

// before
$ dotnet --list-runtimes  # only Microsoft.NETCore.App 10.x
// after
$ apt install dotnet-runtime-8.0

Defensive patterns

Strategy: validation

Validate before calling

import subprocess
out = subprocess.run(["dotnet", "--list-runtimes"], capture_output=True, text=True)
majors = {l.split()[1].split(".")[0] for l in out.stdout.splitlines() if l.startswith("Microsoft.NETCore.App")}
supported = {"4","6","7","8","9"}
if not majors & supported:
    raise EnvironmentError(f"dotnet majors {majors} unsupported; need one of {supported}")

Type guard

def has_supported_dotnet() -> bool:
    try:
        out = subprocess.run(["dotnet","--list-runtimes"], capture_output=True, text=True, check=True)
    except (FileNotFoundError, subprocess.CalledProcessError):
        return False
    supported = {"4","6","7","8","9"}
    return any(l.startswith("Microsoft.NETCore.App") and l.split()[1].split(".")[0] in supported
               for l in out.stdout.splitlines())

Try / catch

try:
    version = get_dotnet_version()
except SolidLSPException as e:
    if "No supported dotnet version" in str(e):
        install_side_by_side_runtime("8.0")  # side-by-side, keeps existing runtimes
    raise

Prevention

Install a supported LTS runtime (8.0) even if a newer major exists — they install side-by-side
Avoid CI images with only EOL (2.1/3.1) or preview-only runtimes
Update the library when new .NET majors are needed
Pin the dotnet runtime version in CI/dockerfiles

When it happens

Trigger: `dotnet --list-runtimes` returns Microsoft.NETCore.App entries only for unsupported majors, e.g. only version 10 (preview/newer) or 2.1/3.1 (EOL) installed.

Common situations: Machines pinned to EOL .NET Core 3.1; brand-new .NET major released before library support; preview-only runtimes installed.

Related errors

AI-assisted analysis of oraios/serena@7fcbca7e62 (2026-08-29). Data as JSON: /api/errors/016ad64077e67a19. Report an issue: GitHub.