I don’t know what started it, as I had been able to compile just fine previously. This is a pretty small test project, but I think it may be the last straw for my using the Uno Platform for development. Everything feels so fragile.
Anyway, this is the error message. It generates several every time I try to build, each message longer than the last:

Severity Code Description Project File Line Suppression State Details
Error (active) CS7013 Name ‘_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestAppMainPageSC1UnoTestAppMainPageSC2UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestAppMainPageSC1UnoTestAppMainPageSC3UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestAppMainPageSC1UnoTestAppMainPageSC2UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestAppMainPageSC1UnoTestAppMainPageSC4UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestAppMainPageSC1UnoTestAppMainPageSC2UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestAppMainPageSC1UnoTestAppMainPageSC3UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestAppMainPageSC1UnoTestAppMainPageSC2UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestAppMainPageSC1UnoTestAppMainPageSC5UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestAppMainPageSC1UnoTestAppMainPageSC2UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestAppMainPageSC1UnoTestAppMainPageSC3UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestAppMainPageSC1UnoTestAppMainPageSC2UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestAppMainPageSC1UnoTestAppMainPageSC4UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestAppMainPageSC1UnoTestAppMainPageSC2UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestAppMainPageSC1UnoTestAppMainPageSC3UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestAppMainPageSC1UnoTestAppMainPageSC2UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestAppMainPageSC1UnoTestAppMainPageSC6UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestAppMainPageSC1UnoTestAppMainPageSC2UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestAppMainPageSC1UnoTestAppMainPageSC3UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestAppMainPageSC1UnoTestAppMainPageSC2UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestAppMainPageSC1UnoTestAppMainPageSC4UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestAppMainPageSC1UnoTestAppMainPageSC2UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestAppMainPageSC1UnoTestAppMainPageSC3UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestAppMainPageSC1UnoTestAppMainPageSC2UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestAppMainPageSC1UnoTestAppMainPageSC5UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestAppMainPageSC1UnoTestAppMainPageSC2UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestAppMainPageSC1UnoTestAppMainPageSC3UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestAppMainPageSC1UnoTestAppMainPageSC2UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestAppMainPageSC1UnoTestAppMainPageSC4UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestAppMainPageSC1UnoTestAppMainPageSC2UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestAppMainPageSC1UnoTestAppMainPageSC3UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestAppMainPageSC1UnoTestAppMainPageSC2UnoTestApp__Resources_MainPage_90def0218f96931edb97aa65fb4dbdbf_UnoTestAppMainPageSC1UnoTestAppMainPageSC7’ exceeds the maximum length allowed in metadata. UnoTestApp (net8.0-desktop) C:UserssamhSourcereposUnoTestAppUnoTestAppobjDebugnet8.0-desktopUno.UI.SourceGeneratorsUno.UI.SourceGenerators.XamlGenerator.XamlCodeGeneratorMainPage_90def0218f96931edb97aa65fb4dbdbf.cs 1230

The only reference I’ve found online so far is a bug report on the Roslyn compiler Github from 2016 that has apparently not been resolved. The project still compiles and runs in the net8.0-windows10.0.19041.

Since the error started, I’ve tried a Clean Solution. No dice. Visual Studio has updated. I updated the Uno extension. Done a fair amount of googling, but I have found very little reference to this error and what is actually causing it.