构建代理上Dotnet Restore失败：PackageSourceMapping未识别私有NuGet源

我用私有NuGet源托管应用依赖包，通过Azure Pipelines构建时遇到了PackageSourceMapping相关的还原问题。已按官方指南完成配置：安装工具并执行packagesourcemapper generate nuget.config --remove-unused-sources生成源映射，本地通过清理NuGet缓存、重启VS、干净还原验证，运行完全正常。

但在构建代理上执行以下任务时，还原失败：

- task: NuGetToolInstaller@1
  displayName: Use latest NuGet
  inputs:
    checkLatest: true

- task: UseDotNet@2
  displayName: 'Use global.json SDK'
  inputs:
    packageType: 'sdk'
    useGlobalJson: true

- task: DotNetCoreCLI@2
  displayName: dotnet restore
  inputs:
    command: 'restore'
    projects: ${{ parameters.solution }}
    feedsToUse: 'config'
    nugetConfigPath: 'NuGet.config'

报错信息：

/Users/runner/work/1/s/tests/MyApp.UnitTests/MyApp.UnitTests.csproj : error NU1100: Unable to resolve 'Acme.MyPackage (>= X.X.X-pre)' for 'net8.0'. PackageSourceMapping is enabled, the following source(s) were not considered: /Users/runner/hostedtoolcache/dotnet/library-packs, feed-MyApp, nuget.org. [/Users/runner/work/1/s/MyApp.sln]

我的NuGet.config配置如下：

包源配置 #

<packageSources>
    <clear />
    <add key="nuget.org" value="https://api.nuget.org/v3/index.json" protocolVersion="3" />
    <add key="Acme" value="https://pkgs.dev.azure.com/Acme/MyApp/_packaging/MyFeed/nuget/v3/index.json" />
</packageSources>

包源映射配置 #

<packageSourceMapping>
  <clear />
  <packageSource key="nuget.org">
    <package pattern="*" />
  </packageSource>
  <packageSource key="Acme">
    <package pattern="Acme.*" />
  </packageSource>
</packageSourceMapping>
<disabledPackageSources>
    <clear />
</disabledPackageSources>

查阅官方文档后仍未找到问题根源。我不理解为何NuGet在已有源映射的情况下完全忽略私有源——即便尝试用PackageSourceMapper生成所有包的显式名称配置，问题依旧。更困惑的是，报错信息里明明列出了私有源，却在解析私有包时不使用它？

内容的提问来源于stack exchange，提问作者Axemasta