Building VMR on a machine that sets NUGET_PACKAGES env variable fails

[ericstj]

I have a DevBox VM that comes with NUGET_PACKAGES=c:\.tools\.nuget\packages

When building the VMR it fails with the following error:

C:\src\dotnet\dotnet\repo-projects\Directory.Build.targets(487,5): error MSB3073: The command "C:\src\dotnet\dotnet\
src\arcade\eng\common\build.cmd -restore -build -pack -publish  -configuration Release -bl /p:DotNetBuildRepo=true /
p:DotNetBuildOrchestrator=true /p:RestoreConfigFile=C:\src\dotnet\dotnet\artifacts\obj\arcade\NuGet.config /p:Source
BuiltAssetsDir=C:\src\dotnet\dotnet\artifacts\assets\Release\ /p:SourceBuiltAssetManifestsDir=C:\src\dotnet\dotnet\a
rtifacts\manifests\arcade\ /p:OfficialBuildId=20241105.1 -msbuildEngine dotnet /p:SourceBuiltShippingPackagesDir=C:\
src\dotnet\dotnet\artifacts\packages\Release\Shipping\arcade\ /p:SourceBuiltNonShippingPackagesDir=C:\src\dotnet\dot
net\artifacts\packages\Release\NonShipping\arcade /p:PortableBuild=true /p:RuntimeOS=win /p:BaseOS=win-x64 /v:minima
l > C:\src\dotnet\dotnet\artifacts\log\Release\arcade\arcade.log 2>&1" exited with code 1. [C:\src\dotnet\dotnet\rep
o-projects\arcade.proj]
  C:\src\dotnet\dotnet\src\arcade\artifacts\toolset\restore.proj : error MSB4242: SDK Resolver Failure: "The SDK res
  olver "UnifiedBuildSdkResolver" failed while attempting to resolve the SDK "Microsoft.DotNet.Arcade.Sdk". Exceptio
  n: "System.IO.DirectoryNotFoundException: Could not find a part of the path 'C:\src\dotnet\dotnet\.packages\micros
  oft.dotnet.arcade.sdk\10.0.0-beta.24551.1'.
  C:\src\dotnet\dotnet\src\arcade\artifacts\toolset\restore.proj : error MSB4242:    at System.IO.Enumeration.FileSy
  stemEnumerator`1.CreateDirectoryHandle(String path, Boolean ignoreNotFound)
  C:\src\dotnet\dotnet\src\arcade\artifacts\toolset\restore.proj : error MSB4242:    at System.IO.Enumeration.FileSy
  stemEnumerator`1.Init()
  C:\src\dotnet\dotnet\src\arcade\artifacts\toolset\restore.proj : error MSB4242:    at System.IO.Enumeration.FileSy
  stemEnumerable`1..ctor(String directory, FindTransform transform, EnumerationOptions options, Boolean isNormalized
  )
  C:\src\dotnet\dotnet\src\arcade\artifacts\toolset\restore.proj : error MSB4242:    at System.IO.Enumeration.FileSy
  stemEnumerableFactory.UserDirectories(String directory, String expression, EnumerationOptions options)
  C:\src\dotnet\dotnet\src\arcade\artifacts\toolset\restore.proj : error MSB4242:    at System.IO.Directory.Internal
  EnumeratePaths(String path, String searchPattern, SearchTarget searchTarget, EnumerationOptions options)
  C:\src\dotnet\dotnet\src\arcade\artifacts\toolset\restore.proj : error MSB4242:    at Microsoft.DotNet.UnifiedBuil
  d.Tasks.UnifiedBuildSdkResolver.SourceBuiltSdkOverride.Create(DictionaryEntry entry) in C:\src\dotnet\dotnet\eng\t
  ools\tasks\Microsoft.DotNet.UnifiedBuild.MSBuildSdkResolver\UnifiedBuildSdkResolver.cs:line 141
  C:\src\dotnet\dotnet\src\arcade\artifacts\toolset\restore.proj : error MSB4242:    at System.Linq.Enumerable.Itera
  torSelectIterator`2.MoveNext()
  C:\src\dotnet\dotnet\src\arcade\artifacts\toolset\restore.proj : error MSB4242:    at System.Linq.Enumerable.IEnum
  erableWhereIterator`1.ToArray()
  C:\src\dotnet\dotnet\src\arcade\artifacts\toolset\restore.proj : error MSB4242:    at Microsoft.DotNet.UnifiedBuil
  d.Tasks.UnifiedBuildSdkResolver.Resolve(SdkReference sdkReference, SdkResolverContext resolverContext, SdkResultFa
  ctory factory) in C:\src\dotnet\dotnet\eng\tools\tasks\Microsoft.DotNet.UnifiedBuild.MSBuildSdkResolver\UnifiedBui
  ldSdkResolver.cs:line 49
  C:\src\dotnet\dotnet\src\arcade\artifacts\toolset\restore.proj : error MSB4242:    at Microsoft.Build.BackEnd.SdkR
  esolution.SdkResolverService.TryResolveSdkUsingSpecifiedResolvers(IReadOnlyList`1 resolvers, Int32 submissionId, S
  dkReference sdk, LoggingContext loggingContext, ElementLocation sdkReferenceLocation, String solutionPath, String
  projectPath, Boolean interactive, Boolean isRunningInVisualStudio, SdkResult& sdkResult, IEnumerable`1& errors, IE
  numerable`1& warnings)""
  Build failed with exit code 1. Check errors above.
  See log: C:\src\dotnet\dotnet\src\arcade\artifacts\log\Release\ToolsetRestore.binlog

I found that this was because some of the packages were being restored to c:\.tools\.nuget\packages while others were going to C:\src\dotnet\dotnet\.packages. It seems that whatever failed here didn't read the package folder from the project, but instead assumed the repo local package folder.

[mmitche]

Dupe of #4598