WebApplicationBuilder throws DirectoryNotFoundException when wwwroot is empty but has links

[TomGathercole]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

The issue occurs if the following happen:

• An Asp.Net Core hosted blazor application is used
• A razor class library is referenced by the client project
• The wwwroot project of the razor class library is empty except for <Content ... Link=wwwroot...> items

Then the application throws System.IO.DirectoryNotFoundException: 'C:\Git\Repro\Repro\RCL\wwwroot\' at startup

Expected Behavior

No exception should be thrown at startup

Steps To Reproduce

https://github.com/TomGathercole/EmptyWwwrootRepro

Exceptions (if any)

System.IO.DirectoryNotFoundException
HResult=0x80070003
Message=C:\Git\Repro\Repro\RCL\wwwroot
Source=Microsoft.Extensions.FileProviders.Physical
StackTrace:
at Microsoft.Extensions.FileProviders.PhysicalFileProvider..ctor(String root, ExclusionFilters filters)
at Microsoft.AspNetCore.Hosting.StaticWebAssets.StaticWebAssetsLoader.<>c.b__1_0(String contentRoot)
at Microsoft.AspNetCore.StaticWebAssets.ManifestStaticWebAssetFileProvider..ctor(StaticWebAssetManifest manifest, Func2 fileProviderFactory) at Microsoft.AspNetCore.Hosting.StaticWebAssets.StaticWebAssetsLoader.UseStaticWebAssetsCore(IWebHostEnvironment environment, Stream manifest) at Microsoft.AspNetCore.Hosting.StaticWebAssets.StaticWebAssetsLoader.UseStaticWebAssets(IWebHostEnvironment environment, IConfiguration configuration) at Microsoft.AspNetCore.Hosting.BootstrapHostBuilder.RunDefaultCallbacks() at Microsoft.AspNetCore.Builder.WebApplicationBuilder..ctor(WebApplicationOptions options, Action1 configureDefaults)
at Microsoft.AspNetCore.Builder.WebApplication.CreateBuilder(String[] args)
at Repro.Program.Main(String[] args) in C:\Git\Repro\Repro\Server\Program.cs:line 9

.NET Version

7.0.306

Anything else?

It looks like C:\Git\Repro\Repro.RCL\wwwroot\ is included under ContentRoots in the Repro.RCL.staticwebassets.runtime.json file, even if the file does not exist. I suppose that this path should not be included if it does not exist, or StaticWebAssetsLoader shouldn't throw if it is missing

Thanks for contacting us.

We're moving this issue to the .NET 9 Planning milestone for future evaluation / consideration. We would like to keep this around to collect more feedback, which can help us with prioritizing this work. We will re-evaluate this issue, during our next planning meeting(s).
If we later determine, that the issue has no community involvement, or it's very rare and low-impact issue, we will close it - so that the team can focus on more important and high impact issues.
To learn more about what to expect next and how this issue will be handled you can read more about our triage process here.

[jon49]

I'm getting the same (or similar) issue once it goes up into the docker container (but not locally in docker). The work around is to not have a razor pages library? Just put it up with the start up project?