Validation error responses ignore custom IProblemDetailsWriter

[Clockwork-Muse]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

I'm trying to change the written format of all ProblemDetails objects for unrelated reasons, but unfortunately I can't seem to get validation errors to use my custom IProblemDetailsWriter instance, it's completely ignored.

My instance is called for the simple set of exception handling (that would generate a 500) or for authentication errors that I've tested with so far, so it's configured and available.
I've tried removing all other writer implementationss at various points in my code and then configuring my instance, but no luck.

Expected Behavior

The provided custom IProblemDetailsWriter is used to write validation errors to the response.

Steps To Reproduce

Clone the provided repro

Start up the application

Make a web request like http://localhost:5285/some?id=750, observe the results do not match the generic "some response" configured in the repro, and setting breakpoints in the relevant methods does not result in trapped execution either.

Exceptions (if any)

None

.NET Version

8.0.415

Anything else?

.NET SDK:
 Version:           8.0.415
 Commit:            7bd5a8c970
 Workload version:  8.0.400-manifests.c414f008
 MSBuild version:   17.11.48+02bf66295

Runtime Environment:
 OS Name:     debian
 OS Version:  12
 OS Platform: Linux
 RID:         linux-x64
 Base Path:   /usr/share/dotnet/sdk/8.0.415/

.NET workloads installed:
Configured to use loose manifests when installing new manifests.
There are no installed workloads to display.

Host:
  Version:      8.0.21
  Architecture: x64
  Commit:       362ab6669d

.NET SDKs installed:
  8.0.415 [/usr/share/dotnet/sdk]

.NET runtimes installed:
  Microsoft.AspNetCore.App 8.0.21 [/usr/share/dotnet/shared/Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 8.0.21 [/usr/share/dotnet/shared/Microsoft.NETCore.App]

Other architectures found:
  None

Environment variables:
  Not set

global.json file:
  Not found

Learn more:
  https://aka.ms/dotnet/info

Download .NET:
  https://aka.ms/dotnet/download

Also repros in net10

[MihuBot]

I'm a bot. Here are possible related and/or duplicate issues (I may be wrong):

• ValidationProblemDetails errors ignored by problem details writer #63345
• DefaultProblemDetailsWriter does not serialize HttpValidationProblemDetails.Errors #45680

[martincostello]

The repro link 404s, so I'm guessing it's private.

[Clockwork-Muse]

@martincostello - Sorry about that, it was misformatted due to copy/paste, corrected.