MSB4018 - DiscoverPrecompressedAssets

[jirisykora83]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

After upgrading to .net 10 i got this error.

    C:\Program Files\dotnet\sdk\10.0.100\Sdks\Microsoft.NET.Sdk.StaticWebAssets\targets\Microsoft.NET.Sdk.StaticWebAssets.Compression.targets(297,5): error MSB4018:
      The "DiscoverPrecompressedAssets" task failed unexpectedly.
      System.ArgumentException: An item with the same key has already been added. Key: C:\Users\jiri\.nuget\packages\microsoft.aspnetcore.app.internal.assets\10.0.0\_framework\blazor.web.js
         at System.Collections.Generic.Dictionary`2.Add(TKey key, TValue value)
         at System.Linq.Enumerable.SpanToDictionary[TSource,TKey](ReadOnlySpan`1 source, Func`2 keySelector, IEqualityComparer`1 comparer)
         at System.Linq.Enumerable.ToDictionary[TSource,TKey](IEnumerable`1 source, Func`2 keySelector, IEqualityComparer`1 comparer)
         at Microsoft.AspNetCore.StaticWebAssets.Tasks.DiscoverPrecompressedAssets.Execute()
         at Microsoft.Build.BackEnd.TaskExecutionHost.Execute()
         at Microsoft.Build.BackEnd.TaskBuilder.ExecuteInstantiatedTask(TaskExecutionHost taskExecutionHost, TaskLoggingContext taskLoggingContext, TaskHost taskHost, ItemBucket bucket, TaskExecutionMode howToExecuteTask)

And i cant found any indication what is wrong.

Expected Behavior

No response

Steps To Reproduce

No response

Exceptions (if any)

No response

.NET Version

10.0.100

Anything else?

No response

[javiercn]

@jirisykora83 thanks for contacting us.

Can you capture a binary log and share it with us to help determine what's happening here?

[jirisykora83]

@javiercn How can I share it? I would prefer not to upload it publicly here. Is there a private way to send you the binary log?

[javiercn]

@jirisykora83 file a visual studio issue through the report a problem dialog in Visual Studio and link it there.

Additionally, you can use msbuild structured log viewer to understand the inputs to the task. What's likely happening is that there are duplicate inputs being injected as inputs.

[jirisykora83]

@jirisykora83 file a visual studio issue through the report a problem dialog in Visual Studio and link it there.

Additionally, you can use msbuild structured log viewer to understand the inputs to the task. What's likely happening is that there are duplicate inputs being injected as inputs.

I would like to doit but i do not know why my VS do not show me option to "Report a Problem" i even try "insider" version but same result. I collect binlog via dotnet build -bl

--

bin log basically show same error

with parameters where it is look like there are all "green" but i just scroll trhu as there is a lot of files (bootstraps icons etc..)

[javiercn]

@jirisykora83 thanks for the additional details.

You can follow these instructions to report a problem through VS: Make sure you link the issue in this ticket and vice versa.
https://learn.microsoft.com/en-us/visualstudio/ide/how-to-report-a-problem-with-visual-studio?view=visualstudio

Alternatively, to producing a binlog, a separate minimal repro as a public github repository would also work.

If your solution is in source control you can also delete files, rebuild and continue deleting files until you no longer are able to reproduce the issue.

Another important thing is to make sure that you cleaned your bin and obj folders after the .NET 8.0 -> 10.0 upgrade.