5.9.0 problems with controller generation using .NET on Ubuntu

[bjornharrtell]

DESCRIPTION

An update from 5.8.1 to 5.9.0 cause unexpected runtime errors.

STEPS TO REPRODUCE

No clean reproduction yet.

EXPECTED BEHAVIOR

Drop in compatibility.

ACTUAL BEHAVIOR

Looks like generated controllers are missing. I have a manual Operations controller and that one still works with intact resource graph.

VERSIONS USED

• JsonApiDotNetCore version: 5.9.0
• ASP.NET Core version: 8.0.21
• Entity Framework Core version: 9.0.10
• Database provider: Npgsql.EntityFrameworkCore.PostgreSQL 9.0.4

[bjornharrtell]

I see these warnings in compilation which could perhaps be a lead:

CSC : warning CS9057: The analyzer assembly '/home/bjorn/.nuget/packages/jsonapidotnetcore.sourcegenerators/5.9.0/analyzers/dotnet/cs/JsonApiDotNetCore.SourceGenerators.dll' references version '4.13.0.0' of the compiler, which is newer than the currently running version '4.8.0.0'.

[bkoelman]

Which compiler version or IDE are you using?

[bjornharrtell]

I use dotnet on the command line, SDK version 8.0.121.

[bjornharrtell]

Attempting to upgrade to SDK version 9.0.111 fails in the same ways, with warning on compile:

CSC : warning CS9057: The analyzer assembly '/home/bjorn/.nuget/packages/jsonapidotnetcore.sourcegenerators/5.9.0/analyzers/dotnet/cs/JsonApiDotNetCore.SourceGenerators.dll' references version '4.13.0.0' of the compiler, which is newer than the currently running version '4.12.0.0'.

[bjornharrtell]

If I use SDK 10.0.100-rc.2.25502.107 I see no issues.

[bkoelman]

There's no need for a .NET 10 (preview/rc) SDK. It isn't installed on our build agents, which succeed without it. They run with the latest SDK versions of .NET 8 and 9.

JADNC 5.9.0 requires Microsoft.CodeAnalysis 4.11.0 or higher. Earlier versions required Microsoft.CodeAnalysis 4.1.0 or higher. Because this is a compile-time dependency, the .NET runtime version is irrelevant. Let's look at the SDK versions for .NET 8, the minimum supported runtime for JADNC 5.9.0.

From looking at the October 2025 release of .NET 8 (at https://dotnet.microsoft.com/en-us/download/dotnet/8.0):

• The binaries for SDK 8.0.121 contain Microsoft.CodeAnalysis 4.8.0. It makes sense that this version is incompatible.
• The binaries for SDK 8.0.415 contain Microsoft.CodeAnalysis 4.11.0, so it should be compatible.

I don't know why multiple SDK versions are offered for the same runtime version. There's some documentation [here[(https://learn.microsoft.com/en-us/dotnet/core/versions/), but that doesn't explain how 8.0.415 is different from 8.0.121 (while both shipped in October 2025). What makes this more confusing is that the lowest version is shown at the top of the download list, unlike earlier releases. So whoever picks the first download is not using the latest version.

The good news is that the code from 5.9.0 could be made compatible with Microsoft.CodeAnalysis 4.8.0. It doesn't use newer APIs. But based on the analysis above, I'm hesitant to downgrade. We've been unable to use newer Roslyn APIs for years, so now that we're changing the minimum version anyway, I'd like to pick a sufficiently high version. There's more guidance at https://andrewlock.net/supporting-multiple-sdk-versions-in-analyzers-and-source-generators/, though I don't like the idea of supporting multiple Roslyn versions, because it's a lot of work for something that's just a utility.

I'm going to restore a years-old Windows backup without any .NET bits on it and install the latest .NET 8 SDK 8.0.415 on that, to verify I can compile JADNC 5.9.0 against that.

[bkoelman]

JADNC 5.9.0 requires Microsoft.CodeAnalysis 4.11.0 or higher.

This isn't true. It requires 4.13 or higher, so it is incompatible with the latest .NET 8 SDK 8.0.415. But the latest .NET 9 SDK 9.0.306 ships with 4.14, so that one should be compatible.

Therefore, my plan is to release a patch to downgrade to 4.11. This enables .NET 8 users to stay on LTS and build with the latest .NET 8 SDK (8.0.415, but not 8.0.121).

@bjornharrtell What's the reason you chose to test with SDK 9.0.111 instead of 9.0.306? Do you know what the differences are? Is there a reason we should support the lower version that I'm unaware of?

[bkoelman]

The release notes at https://github.com/dotnet/sdk/releases don't mention them at all:

[bjornharrtell]

@bkoelman I'm running Ubuntu most of the time and locally I use .NET as delivered to Ubuntu via the built in package channels which seem to have lower SDK than the same .NET release version from Microsoft does. It's likely due to some Ubuntu policies about what is allowed to backport onto a LTS release and perhaps also technical reasons if Ubuntu builds against shared libraries delivered with the Ubuntu release vs. Microsoft that probably statically compiles alot more into a binary release of .NET and can be more aggressively upgrading dependencies.

• https://launchpad.net/ubuntu/+source/dotnet8
• https://launchpad.net/ubuntu/+source/dotnet9

Anyways, it's just the most straight forward and easy way to get .NET on Ubuntu, no other reason really.

[bkoelman]

Thanks, I understand now.

Would it be okay for you to build against the low version 9.0.111 of the .NET 9 SDK? That one ships with Microsoft.CodeAnalysis 4.12, so it should be compatible after I've patched JADNC to require 4.11 or higher.

Note that this is only for building your sources. The app itself still runs on .NET 8.