Remove Compiler.ReportCompileDiagnostics - this was only used in non-tools mode and was double printing something already handled in CompileGroup Merge codegen diagnostics into Compiler.Diagnostics so errors/warnings show in editor error list or console in non-tools If codegen reports any diagnostics of error severity, fail the build ( warnings won't fail the build ) Clean up some generator diagnostic descriptors, make them more clear, set severity to warning on warnings.. Non-static ConCmd.Client errors