在 dockerfile 中构建项目时，“无法找到后备包文件夹”nuget 错误来自哪里？

Question

When building, from a dockerfile, I get this:

/usr/share/dotnet/sdk/3.1.102/Sdks/Microsoft.NET.Sdk/targets/Microsoft.PackageDependencyResolution.targets(234,5): error MSB4018: The "ResolvePackageAssets" task failed unexpectedly. [/src/test/test.fsproj]
/usr/share/dotnet/sdk/3.1.102/Sdks/Microsoft.NET.Sdk/targets/Microsoft.PackageDependencyResolution.targets(234,5): error MSB4018: NuGet.Packaging.Core.PackagingException: Unable to find fallback package folder '/usr/local/share/dotnet/sdk/NuGetFallbackFolder'. [/src/test/test.fsproj]
/usr/share/dotnet/sdk/3.1.102/Sdks/Microsoft.NET.Sdk/targets/Microsoft.PackageDependencyResolution.targets(234,5): error MSB4018:    at NuGet.Packaging.FallbackPackagePathResolver..ctor(String userPackageFolder, IEnumerable`1 fallbackPackageFolders) [/src/test/test.fsproj]
/usr/share/dotnet/sdk/3.1.102/Sdks/Microsoft.NET.Sdk/targets/Microsoft.PackageDependencyResolution.targets(234,5): error MSB4018:    at Microsoft.NET.Build.Tasks.NuGetPackageResolver.CreateResolver(IEnumerable`1 packageFolders) [/src/test/test.fsproj]
/usr/share/dotnet/sdk/3.1.102/Sdks/Microsoft.NET.Sdk/targets/Microsoft.PackageDependencyResolution.targets(234,5): error MSB4018:    at Microsoft.NET.Build.Tasks.NuGetPackageResolver.CreateResolver(LockFile lockFile) [/src/test/test.fsproj]
/usr/share/dotnet/sdk/3.1.102/Sdks/Microsoft.NET.Sdk/targets/Microsoft.PackageDependencyResolution.targets(234,5): error MSB4018:    at Microsoft.NET.Build.Tasks.ResolvePackageAssets.CacheWriter..ctor(ResolvePackageAssets task) [/src/test/test.fsproj]
/usr/share/dotnet/sdk/3.1.102/Sdks/Microsoft.NET.Sdk/targets/Microsoft.PackageDependencyResolution.targets(234,5): error MSB4018:    at Microsoft.NET.Build.Tasks.ResolvePackageAssets.CacheReader.CreateReaderFromDisk(ResolvePackageAssets task, Byte[] settingsHash) [/src/test/test.fsproj]
/usr/share/dotnet/sdk/3.1.102/Sdks/Microsoft.NET.Sdk/targets/Microsoft.PackageDependencyResolution.targets(234,5): error MSB4018:    at Microsoft.NET.Build.Tasks.ResolvePackageAssets.CacheReader..ctor(ResolvePackageAssets task) [/src/test/test.fsproj]
/usr/share/dotnet/sdk/3.1.102/Sdks/Microsoft.NET.Sdk/targets/Microsoft.PackageDependencyResolution.targets(234,5): error MSB4018:    at Microsoft.NET.Build.Tasks.ResolvePackageAssets.ReadItemGroups() [/src/test/test.fsproj]
/usr/share/dotnet/sdk/3.1.102/Sdks/Microsoft.NET.Sdk/targets/Microsoft.PackageDependencyResolution.targets(234,5): error MSB4018:    at Microsoft.NET.Build.Tasks.ResolvePackageAssets.ExecuteCore() [/src/test/test.fsproj]
/usr/share/dotnet/sdk/3.1.102/Sdks/Microsoft.NET.Sdk/targets/Microsoft.PackageDependencyResolution.targets(234,5): error MSB4018:    at Microsoft.NET.Build.Tasks.TaskBase.Execute() [/src/test/test.fsproj]
/usr/share/dotnet/sdk/3.1.102/Sdks/Microsoft.NET.Sdk/targets/Microsoft.PackageDependencyResolution.targets(234,5): error MSB4018:    at Microsoft.Build.BackEnd.TaskExecutionHost.Microsoft.Build.BackEnd.ITaskExecutionHost.Execute() [/src/test/test.fsproj]
/usr/share/dotnet/sdk/3.1.102/Sdks/Microsoft.NET.Sdk/targets/Microsoft.PackageDependencyResolution.targets(234,5): error MSB4018:    at Microsoft.Build.BackEnd.TaskBuilder.ExecuteInstantiatedTask(ITaskExecutionHost taskExecutionHost, TaskLoggingContext taskLoggingContext, TaskHost taskHost, ItemBucket bucket, TaskExecutionMode howToExecuteTask) [/src/test/test.fsproj]

Build FAILED.

Answer 1

Multiple things are coming to my mind.

1: Edit csproj with the below tag:

  <PropertyGroup>
    <RestoreFallbackFolders>clear</RestoreFallbackFolders>
  </PropertyGroup>

2: Update Dockerfile.

The dotnet sdk does not have the error folder.

root@bd6d24a2e56b:/# cd /usr/local/share/dotnet/sdk/NuGetFallbackFolder
bash: cd: /usr/local/share/dotnet/sdk/NuGetFallbackFolder: No such file or directory

Add a RUN command under FROM:

FROM mcr.microsoft.com/dotnet/core/sdk:3.1 as build
RUN mkdir -p /usr/local/share/dotnet/sdk/NuGetFallbackFolder

Hope this helps.

Answer 2

I downloaded a ZIP project and on building it faced the same issue. This issue was resolved by checking the source of nuget packages- Tools->Nuget Package Manager-> Package Manager Settings-> Nuget Package Manager-> Package Sources

Check the sources of the packages. This might be causing the issue.

Answer 3

Had the same issue. After some Googling I found this nice issue: https://github.com/dotnet/dotnet-docker/issues/2050

To recap the answer there: if you have already built the project outside of Docker, then you will have output folders which will get copied into the Docker build environment causing this problem.

The solution is then to add a .dockerignore file which prevents this from happening. Something small like this should do the trick:

# directories
**/bin/
**/obj/
**/out/

# files
Dockerfile*
**/*.md

Answer 4

要解决此错误“无法找到回退包文件夹”，您需要在该目录中创建一个空文件夹，如下所示：/usr/local/share/dotnet/sdk/NuGetFallbackFolder