.NET Hot Reload not working with .NET 6 Preview 7 and dotnet watch

[danroth27]

Repro steps:

• Install .NET 6 Preview 7 (6.0.100-preview.7.21366.53)
• dotnet new blazorserver -o BlazorApp
• cd BlazorApp
• dotnet watch
• Edit Pages\Index.razor

Expected result: UI updates with changes

Actual result:

• dotnet watch says the change was applied, and the browser flashes with the hot reload overlay, but the UI isn't updated.

@pranavkm

[pranavkm]

@mikem8361 it looks like MetadataUpdater.IsSupported returns false when running under dotnet-watch. Does not seem to be the case for Mono / WebAssembly. Here's a simple repro:

• dotnet new console
• Edit Program.cs to print Console.WriteLine(System.Reflection.Metadata.MetadataUpdater.IsSupported);
• dotnet watch

This prints False and causes some of our wire-up to fail. Could you look?

[mikem8361]

Fixed in PR dotnet/runtime#55874