With .NET Core 3.0 Preview 8 announced, there is one breaking change that did not seem to be mentioned.
After updating my client-side Blazor project to Preview 8 and fixing any breaking changes mentioned in the updates blog post I was still getting build failures. Unfortunately the Mono build errors are hard to read and diagnose. There is an open issue in Mono repo, so hopefully this will get addressed at some point.
After a few sanity checks, reinstalling the SDK, double checking there were no updates that I had missed. I noticed that I had a package that was still on preview 7 but there was no preview 8 update available. The package was
Microsoft.AspNetCore.Components.Browser and there was nothing about it in the update notes. Searching through the AspNetCore repo on GitHub I found a comment stating that
Microsoft.AspNetCore.Components.Browser had been renamed to
Microsoft.AspNetCore.Components.Web. And sure enough there was a preview 8 Nuget package for it available.
Swapping the packages, normality was restored.
Watch out for this one, as it seems to be an undocumented change but an important one!