chocolatey/choco · error · NotSupportedException

The '{0}' source does not support searching for packages

Error message

The '{0}' source does not support searching for packages

What it means

Thrown as a NotSupportedException when a non-normal source type (e.g. cygwin, python, ruby, windowsfeatures) fails to return search or list results. PerformSourceRunnerFunction resolves an ISearchableSourceRunner (or IListSourceRunner for LocalOnly) for the configured SourceType; if no registered runner implements that interface the function returns default (null), and the subsequent null-check fires this exception. The exact message variant depends on config.ListCommand.LocalOnly — 'listing' vs 'searching'.

Source

Thrown at src/chocolatey/infrastructure.app/services/ChocolateyPackageService.cs:281

            IEnumerable<PackageResult> results;

            if (config.ListCommand.LocalOnly && !config.SourceType.IsEqualTo(SourceTypes.Normal))
            {
                results = PerformSourceRunnerFunction<IListSourceRunner, IEnumerable<PackageResult>>(config, runner => runner.List(config));
            }
            else if (config.SourceType.IsEqualTo(SourceTypes.Normal))
            {
                results = _nugetService.List(config).OrEmpty();
            }
            else
            {
                results = PerformSourceRunnerFunction<ISearchableSourceRunner, IEnumerable<PackageResult>>(config, runner => runner.Search(config));
            }

            if (results is null)
            {
                var message = config.ListCommand.LocalOnly ? "The '{0}' source does not support listing of packages".FormatWith(config.SourceType) : "The '{0}' source does not support searching for packages".FormatWith(config.SourceType);
                throw new NotSupportedException(message);
            }

            foreach (PackageResult package in results)
            {
                if (config.SourceType.IsEqualTo(SourceTypes.Normal))
                {
                    if (!config.ListCommand.IncludeRegistryPrograms)
                    {
                        yield return package;
                    }

                    if (config.ListCommand.LocalOnly && config.ListCommand.IncludeRegistryPrograms && package.PackageMetadata != null)
                    {
                        packages.Add(package);
                    }
                }
            }

View on GitHub (pinned to 0d5abdd10c)

Solutions

  1. Verify the --source-type value is valid and that its corresponding runner implements ISearchableSourceRunner or IListSourceRunner.
  2. If using a normal NuGet/Chocolatey feed, ensure config.SourceType equals SourceTypes.Normal so the _nugetService.List path is taken instead of the runner path.
  3. For custom alternative source runners, implement the ISearchableSourceRunner interface (Search method) or IListSourceRunner (List method) on the runner class and register it in the container.
  4. If listing locally installed packages, set config.ListCommand.LocalOnly = true and ensure the runner implements IListSourceRunner.

Example fix

// before: runner missing the interface
public class MyCustomRunner : IAlternativeSourceRunner
{
    // no Search or List implementation
}

// after: implement the required interface
public class MyCustomRunner : IAlternativeSourceRunner, ISearchableSourceRunner
{
    public IEnumerable<PackageResult> Search(ChocolateyConfiguration config)
    {
        // return results, never null
        return Enumerable.Empty<PackageResult>();
    }
}
Defensive patterns

Strategy: validation

Validate before calling

// Before calling List, verify the source type supports the operation
var supportedSourceTypes = new[] { SourceTypes.Normal, SourceTypes.Cygwin, SourceTypes.Python, SourceTypes.WindowsFeatures };
if (!supportedSourceTypes.Contains(config.SourceType, StringComparer.OrdinalIgnoreCase))
{
    throw new InvalidOperationException($"Unsupported source type: {config.SourceType}");
}
if (!config.SourceType.IsEqualTo(SourceTypes.Normal))
{
    var runners = _containerResolver.ResolveAll<ISearchableSourceRunner>();
    if (!runners.Any(r => r.SourceType.IsEqualTo(config.SourceType)))
    {
        // warn user before the API call fails
        throw new InvalidOperationException($"Source type '{config.SourceType}' has no runner implementing ISearchableSourceRunner.");
    }
}

Type guard

public static bool SourceTypeSupportsSearch(string sourceType, IEnumerable<IAlternativeSourceRunner> registeredRunners)
{
    if (sourceType.IsEqualTo(SourceTypes.Normal)) return true;
    return registeredRunners.OfType<ISearchableSourceRunner>().Any(r => r.SourceType.IsEqualTo(sourceType));
}

Try / catch

try
{
    var results = _packageService.List(config);
    foreach (var pkg in results) { /* process */ }
}
catch (NotSupportedException ex) when (ex.Message.Contains("does not support"))
{
    // Surface a user-friendly message about unsupported source type
    logger.Error($"Source type '{config.SourceType}' cannot search. Use --source-type=normal or install the appropriate runner.");
}

Prevention

When it happens

Trigger: Calling List() on ChocolateyPackageService with config.SourceType set to an alternative source (not 'normal') when either (a) no alternative source runner implementing ISearchableSourceRunner/IListSourceRunner is registered in the DI container, or (b) the resolved runner exists but its Search/List method returns null. The LocalOnly flag selects the runner interface and the error message variant.

Common situations: A user or automation script runs 'choco search --source-type python' or 'choco list --local-only --source-type windowsfeatures' against a source type whose runner does not implement the required search/list interface. Also occurs when a custom alternative source runner is registered but missing the ISearchableSourceRunner interface implementation.

Related errors

AI-assisted analysis of chocolatey/choco@0d5abdd10c (2026-08-13). Data as JSON: /api/errors/4fb4ce4aad8cc416. Report an issue: GitHub.