CreateAppHost runs and fails during VS design time build if project isn't already built

Repro steps

1. Install .NET Core 3.0 SDK (I had 3.0.100-alpha1-009697)
2. dotnet new wpf
3. Open VS.
4. Open the project created in 2.

Result

Error    MSB4018    The "CreateAppHost" task failed unexpectedly.
Microsoft.NET.Build.Tasks.ResourceUpdater+HResultException: 80070002
   at Microsoft.NET.Build.Tasks.ResourceUpdater.AddResourcesFromPEImage(String peFile)
   at Microsoft.NET.Build.Tasks.AppHost.Create(String appHostSourceFilePath, String appHostDestinationFilePath, String appBinaryFilePath, Boolean windowsGraphicalUserInterface, String intermediateAssembly, Logger log)
   at Microsoft.NET.Build.Tasks.CreateAppHost.ExecuteCore()
   at Microsoft.NET.Build.Tasks.TaskBase.Execute()
   at Microsoft.Build.BackEnd.TaskExecutionHost.Microsoft.Build.BackEnd.ITaskExecutionHost.Execute()
   at Microsoft.Build.BackEnd.TaskBuilder.<ExecuteInstantiatedTask>d__26.MoveNext()

(from C:\Program Files\dotnet\sdk\3.0.100-alpha1-009697\Sdks\Microsoft.NET.Sdk\targets\Microsoft.NET.Sdk.targets Line 293)

Expected

We probably shouldn’t run this target if the assemblies it’s going to work on don’t exist.

[bzapata-thr]

Figured it out. For anyone viewing this thread, the culprit was Windows Security. I was getting the above error about 40% of the time I did a build (F5 and Control-F5). The fix:

• go to Virus & threat protection

Manage settings Add or remove exclusions Add an exclusion to the parent folder for all your repositories

I didn’t see this specific fix anywhere else on the web, so hopefully this helps someone.

[Lakritzator]

Hi Nick, thanks for writing that.

I’m not frustrated, in fact I think you are doing a great job by doing this in the open, which is certainly not easy. And I am sorry if that comment felt like stressing you, I actually didn’t think about that. I really wanted to prevent something I had experienced, like issue x was fixed but it wasn’t clear in which build it arrives. I have no problems at all waiting much longer for a fix, especially if this gives you time to improve the build pipeline and maybe even make something like rudimentary release notes. And there are probably issues which deserve a higher priority!

I know what it means to run alpha or beta software, I wouldn’t be doing this if it doesn’t bring something. This makes it possible to adapt my product way quicker than to wait until it’s released. It also gives me a possibility to influence the framework with some of my experiences, and learn something while doing this. For instance: I actually learned today that there is no such thing as an “Any Cpu” .exe, it’s a .NET Framework thing. I should bring this up with Daniel. It’s a mystery why I didn’t know… but not having this this does complicate my product and a lot of others.

I actually got most of the foundation code for Greenshot running on dotnet core 3.0, it might still have a few small quirks, but this is really amazing work in such a short time!!! Just seeing the shear amount of APIs that you guy processed, is mind boggling. I hope to have a running Greenshot soon, much sooner as I expected!