Wait ignored when a SqlProject waits for another SqlProject

[samgibsonmoj]

Describe the bug

When configuring dependency ordering between SQL projects using .WaitForCompletion(), the call is ignored and both SQL projects run in parallel. This only happens for SQL-to-SQL dependencies, the same call works as expected when a non-SQL project waits for completion of a SQL project.

var builder = DistributedApplication.CreateBuilder(args);

var sql = builder.AddSqlServer("sql");

var exampleDb = sql.AddDatabase("ExampleDb");
var exampleDbTwo = sql.AddDatabase("ExampleDb2");

var exampleDbSqlProj = builder.AddSqlProject<ExampleDb>("Example")
    .WithReference(exampleDb);

builder.AddSqlProject<ExampleDbTwo>("ExampleTwo")
    .WithReference(exampleDbTwo)
    .WaitForCompletion(exampleDbSqlProj); // Ignored

builder.AddProject<ExampleApp>("ExampleApp")
    .WaitForCompletion(exampleDbSqlProj); // Interestingly, not ignored!

Regression

No response

Steps to reproduce

1. Create a new Aspire distributed application.
2. Add a SQL Server resource to the application.
3. Add two SQL database resources (e.g., ExampleDb and ExampleDb2) to the SQL Server instance.
4. Create two SQL project resources in the solution (e.g., Example and ExampleTwo)
5. Configure the second SQL project to wait for the first using .WaitForCompletion().
6. Run the application.

Observe that both SQL projects deploy in parallel, and the .WaitForCompletion() call between the two SQL projects is ignored.

Add another non-SQL project (e.g., a web app) and configure it to .WaitForCompletion() on the first SQL project — note that this behaves correctly and waits.

Expected behavior

I would expect the first SQL Project to wait for the second one, replicating the behaviour of non-SQL projects waiting for SQL projects.

Screenshots

No response

IDE and version

Other

IDE version

VS2026 Insiders [11116.177]

Nuget packages

Aspire.Hosting.AppHost (9.5.2)
Aspire.Hosting.SqlServer (9.5.2)
CommunityToolkit.Aspire.Hosting.SqlDatabaseProjects (9.8.1-beta.424)

Additional context

No response

Help us help you

No, just wanted to report this

[samgibsonmoj]

This was also explained here under a separate (but related) closed issue.

[ErikEJ]

Ha! This briefly worked, then this piece of code was removed due to some changes in Aspire 9.2:

            if (target is SqlServerDatabaseResource)
            {
                await resourceNotificationService.WaitForDependenciesAsync(resource, cancellationToken);
            }

@aaronpowell @jmezach Any ideas how to get this working again??

[ErikEJ]

@aaronpowell f99d342#diff-36a856c6ba62395fbc4181da20ef499ff3a6def90f322b6a1ebf463fc1600509R103

[aaronpowell]

Managed to track down the actual commit to get the proper commit message - af74f71

The message suggests that there was a circular reference in the dependency chain which is causing the waiting to get stuck.

Maybe it was the tests that we have in place that are causing it and masking a real scenario? Looking at the scenario in the bug I don't see how that'd result in a circular dependency, so it could be valid to put back in.

[ErikEJ]

@aaronpowell @jmezach I tried to bring it back, it it was just hanging and never exiting the wait call - so not the proper solution as far as I can tell.

[jmezach]

@ErikEJ What does your Aspire app look like?

[ErikEJ]

@jmezach Basically just like the app above:

var builder = DistributedApplication.CreateBuilder(args);

var server = builder.AddSqlServer("sql");

var database = server.AddDatabase("TargetDatabase");

var otherDatabase = server.AddDatabase("OtherTargetDatabase");

var sdkProject = builder.AddSqlProject<Projects.SdkProject>("sdk-project")
       .WithReference(database);

var otherProject = builder.AddSqlProject<Projects.SdkProject>("other-sdk-project")
       .WithReference(otherDatabase)
       .WaitForCompletion(sdkProject);

[jmezach]

@ErikEJ Hmm, and with that change the otherProject is waiting indefinitely?

[ErikEJ]

Running in the debugger looks like they both wait indefinitely 😢

[jmezach]

@ErikEJ That's interesting. I'm assuming then that sdkProject is waiting for database and that otherProject is waiting for both database and sdkProject?

[jmezach]

Looking at the docs for WaitForDependenciesAsync it explicitly calls out that it is waiting for all dependencies to be ready. Are we even publishing a resource ready event?

[ErikEJ]

@jmezach It looks like we do:

Aspire/src/CommunityToolkit.Aspire.Hosting.SqlDatabaseProjects/SqlProjectPublishService.cs

Line 75 in a22d4f8

await eventing.PublishAsync(new ResourceReadyEvent(resource, serviceProvider), cancellationToken);

[jmezach]

I'm wondering now what I was thinking when I originally wrote that ;). We were checking if the target is a SqlServerDatabaseResource and if it is we wait for dependencies of the resource, ie. the SQL Server Database Project resource itself. But that won't become Healthy until after we've done the waiting. So I guess it makes sense that it waits indefinitely because it is waiting for a ResourceReadyEvent that is only being published later in that same method.

I do think we'll want to wait for the target database resource to be Healthy before we even attempt to publish the database since it will most likely fail. Then the next question is how we're going to wait for any other resources without locking ourselves up ;).

[ErikEJ]

@jmezach Waiting for the target database to be ready works fine as far as I can tell, it is waiting for another IReeosurceWithDacpac that fails.

[jmezach]

@ErikEJ Does adding this code back work with only a single SqlProject? I would assume it is then also stuck waiting indefinitely?

            if (target is SqlServerDatabaseResource)
            {
                await resourceNotificationService.WaitForDependenciesAsync(resource, cancellationToken);
            }