Compiler Warning ASPIREEXPORT010

Version introduced: 13.2

Exported builder method '0' directly invokes synchronous delegate parameter '1'. Defer the callback, expose an async delegate, or set RunSyncOnBackgroundThread = true to avoid polyglot deadlocks.

This diagnostic warning is reported when an [AspireExport] method directly invokes a synchronous delegate parameter inline, inside the method body. In a multi-language (polyglot) app host, callbacks crossing the language boundary are dispatched through an async messaging channel. If a synchronous callback is invoked inline, it can block the calling thread while the message dispatcher is also waiting on the same thread, causing a deadlock. To avoid this, the callback should be deferred, exposed as an async delegate, or run on a background thread.

Example

The following code generates ASPIREEXPORT010:

C# — Integration.cs

[AspireExport("withConfiguration")]
public static IResourceBuilder<RedisResource> WithConfiguration(
    IResourceBuilder<RedisResource> builder,
    Action<RedisConfiguration> configure)
{
    var config = new RedisConfiguration();
    configure(config);  // Synchronous callback invoked inline — may deadlock
    return builder.WithEnvironment("REDIS_CONFIG", config.ToConnectionString());
}

To correct this warning

Use one of the following approaches:

Option 1: Defer the callback by wrapping it with .WithEnvironment or a similar deferred-execution pattern:

C# — Integration.cs

[AspireExport("withConfiguration")]
public static IResourceBuilder<RedisResource> WithConfiguration(
    IResourceBuilder<RedisResource> builder,
    Action<RedisConfiguration> configure)
{
    return builder.WithEnvironment(context =>
    {
        var config = new RedisConfiguration();
        configure(config);
        context.EnvironmentVariables["REDIS_CONFIG"] = config.ToConnectionString();
    });
}

Option 2: Accept an async delegate instead of a synchronous one:

C# — Integration.cs

[AspireExport("withConfiguration")]
public static IResourceBuilder<RedisResource> WithConfiguration(
    IResourceBuilder<RedisResource> builder,
    Func<RedisConfiguration, Task> configure)
{
    return builder.WithEnvironment(async context =>
    {
        var config = new RedisConfiguration();
        await configure(config);
        context.EnvironmentVariables["REDIS_CONFIG"] = config.ToConnectionString();
    });
}

Suppress the warning

Suppress the warning with either of the following methods:

• Set the severity of the rule in the .editorconfig file.

  .editorconfig

  [*.{cs,vb}]
  dotnet_diagnostic.ASPIREEXPORT010.severity = none

  For more information about editor config files, see Configuration files for code analysis rules.

• Add the following PropertyGroup to your project file:

  C# project file

  <PropertyGroup>
      <NoWarn>$(NoWarn);ASPIREEXPORT010</NoWarn>
  </PropertyGroup>