NullReferenceException in Imageflow BuildJobResult.From on x86 with Dynamic PGO #136844

Description

With PGO the attached minimal project running on x86 fails after ~60 iterations throwing NRE. Setting DOTNET_TieredPGO=0 or DOTNET_TieredCompilation=0 makes it pass.

Reproduction Steps

ImageflowPgoRepro.zip

dotnet run -c Release -- image.png

Expected behavior

200 iterations complete without error.

Actual behavior

After ~63 iterations, ImageJob.FinishAsync throws:

System.NullReferenceException: Object reference not set to an instance of an object.
   at Imageflow.Fluent.BuildJobResult.From(IJsonResponse response, Dictionary`2 outputs)
   at Imageflow.Fluent.ImageJob.FinishAsync(...)

The native JSON response at the failing iteration is valid and complete (code 200, all fields present).

Regression?

No response

Known Workarounds

DOTNET_TieredPGO=0 or DOTNET_TieredCompilation=0

Configuration

• dotnet 10.0.403
• Windows 11 (locally) + Azure Function App (deployed)
• x86

Other information

No response