Log showing NuGet failure when an unrelated source fails to pull, when nuget.org is fine.

NuGet-Unrelated-Source-Fail.log

Installing NuGet package Microsoft.Owin.Host.SystemWeb.3.0.1.
Successfully installed 'Microsoft.Owin.Host.SystemWeb.3.0.1' to WebApplication2
========== Finished ==========
PATH=.\node_modules\.bin;C:\Program Files (x86)\Microsoft Visual Studio 14.0\Common7\IDE\Extensions\Microsoft\Web Tools\External;%PATH%;C:\Program Files (x86)\Microsoft Visual Studio 14.0\Common7\IDE\Extensions\Microsoft\Web Tools\External\git
C:\Users\ncraver.STACKEXCHANGE\.dnx\runtimes\dnx-clr-win-x86.1.0.0-beta5\bin\dnx.exe "C:\Users\ncraver.STACKEXCHANGE\.dnx\runtimes\dnx-clr-win-x86.1.0.0-beta5\bin\lib\Microsoft.Framework.PackageManager\Microsoft.Framework.PackageManager.dll" restore "c:\users\ncraver.stackexchange\documents\visual studio 2015\Projects\WebApplication2\src\WebApplication2" -f "C:\Program Files (x86)\Microsoft Web Tools\DNU"
Microsoft .NET Development Utility CLR-x86-1.0.0-beta5-12103
Restoring packages for c:\users\ncraver.stackexchange\documents\visual studio 2015\Projects\WebApplication2\src\WebApplication2\project.json
  GET https://www.nuget.org/api/v2/
  OK https://www.nuget.org/api/v2/ 459ms
  GET https://build.server.internal/httpAuth/app/nuget/v1/FeedService.svc/
  OK https://build.server.internal/httpAuth/app/nuget/v1/FeedService.svc/ 244ms
  GET https://www.nuget.org/api/v2/FindPackagesById()?id='Microsoft.Owin.Host.SystemWeb'
  GET https://build.server.internal/httpAuth/app/nuget/v1/FeedService.svc/FindPackagesById()?id='Microsoft.Owin.Host.SystemWeb'
  OPEN C:\Program Files (x86)\Microsoft Web Tools\DNU\System.IO\4.0.0-beta-23019\System.IO.nuspec
  OPEN C:\Program Files (x86)\Microsoft Web Tools\DNU\System.Text.Encoding\4.0.0-beta-23019\System.Text.Encoding.nuspec
  GET https://www.nuget.org/api/v2/FindPackagesById()?id='System.Globalization'
  GET https://build.server.internal/httpAuth/app/nuget/v1/FeedService.svc/FindPackagesById()?id='System.Globalization'
  GET https://www.nuget.org/api/v2/FindPackagesById()?id='System.Runtime'
  GET https://build.server.internal/httpAuth/app/nuget/v1/FeedService.svc/FindPackagesById()?id='System.Runtime'
  OPEN C:\Program Files (x86)\Microsoft Web Tools\DNU\System.Threading.Tasks\4.0.0-beta-23019\System.Threading.Tasks.nuspec
  GET https://www.nuget.org/api/v2/FindPackagesById()?id='System.Reflection'
  GET https://build.server.internal/httpAuth/app/nuget/v1/FeedService.svc/FindPackagesById()?id='System.Reflection'
  GET https://www.nuget.org/api/v2/FindPackagesById()?id='System.Collections'
  GET https://build.server.internal/httpAuth/app/nuget/v1/FeedService.svc/FindPackagesById()?id='System.Collections'
  GET https://www.nuget.org/api/v2/FindPackagesById()?id='System.Runtime.Extensions'
  GET https://build.server.internal/httpAuth/app/nuget/v1/FeedService.svc/FindPackagesById()?id='System.Runtime.Extensions'
  OPEN C:\Program Files (x86)\Microsoft Web Tools\DNU\System.Dynamic.Runtime\4.0.0-beta-23019\System.Dynamic.Runtime.nuspec
  OPEN C:\Program Files (x86)\Microsoft Web Tools\DNU\System.Linq.Expressions\4.0.0-beta-23019\System.Linq.Expressions.nuspec
  GET https://www.nuget.org/api/v2/FindPackagesById()?id='System.Threading'
Warning: FindPackagesById: Microsoft.Owin.Host.SystemWeb
  Response from https://build.server.internal/httpAuth/app/nuget/v1/FeedService.svc/FindPackagesById()?id='Microsoft.Owin.Host.SystemWeb' is not a valid NuGet v2 service response.
  GET https://build.server.internal/httpAuth/app/nuget/v1/FeedService.svc/FindPackagesById()?id='Microsoft.Owin.Host.SystemWeb'
  GET https://build.server.internal/httpAuth/app/nuget/v1/FeedService.svc/FindPackagesById()?id='System.Threading'
  GET https://www.nuget.org/api/v2/FindPackagesById()?id='System.Xml.ReaderWriter'
  GET https://build.server.internal/httpAuth/app/nuget/v1/FeedService.svc/FindPackagesById()?id='System.Xml.ReaderWriter'
  GET https://www.nuget.org/api/v2/FindPackagesById()?id='System.Collections.Concurrent'
  GET https://build.server.internal/httpAuth/app/nuget/v1/FeedService.svc/FindPackagesById()?id='System.Collections.Concurrent'
  GET https://www.nuget.org/api/v2/FindPackagesById()?id='System.Threading.ThreadPool'
  GET https://build.server.internal/httpAuth/app/nuget/v1/FeedService.svc/FindPackagesById()?id='System.Threading.ThreadPool'
  GET https://www.nuget.org/api/v2/FindPackagesById()?id='System.Runtime.InteropServices'
Warning: FindPackagesById: Microsoft.Owin.Host.SystemWeb
  Response from https://build.server.internal/httpAuth/app/nuget/v1/FeedService.svc/FindPackagesById()?id='Microsoft.Owin.Host.SystemWeb' is not a valid NuGet v2 service response.
  GET https://build.server.internal/httpAuth/app/nuget/v1/FeedService.svc/FindPackagesById()?id='Microsoft.Owin.Host.SystemWeb'
  GET https://build.server.internal/httpAuth/app/nuget/v1/FeedService.svc/FindPackagesById()?id='System.Runtime.InteropServices'
  GET https://www.nuget.org/api/v2/FindPackagesById()?id='System.Diagnostics.Debug'
  GET https://build.server.internal/httpAuth/app/nuget/v1/FeedService.svc/FindPackagesById()?id='System.Diagnostics.Debug'
Error: FindPackagesById: Microsoft.Owin.Host.SystemWeb
  Response from https://build.server.internal/httpAuth/app/nuget/v1/FeedService.svc/FindPackagesById()?id='Microsoft.Owin.Host.SystemWeb' is not a valid NuGet v2 service response.
Warning: FindPackagesById: System.Globalization
  Response from https://build.server.internal/httpAuth/app/nuget/v1/FeedService.svc/FindPackagesById()?id='System.Globalization' is not a valid NuGet v2 service response.
  GET https://build.server.internal/httpAuth/app/nuget/v1/FeedService.svc/FindPackagesById()?id='System.Globalization'
  OPEN C:\Program Files (x86)\Microsoft Web Tools\DNU\System.ObjectModel\4.0.0-beta-23019\System.ObjectModel.nuspec
  GET https://www.nuget.org/api/v2/FindPackagesById()?id='System.Diagnostics.Tracing'
Warning: FindPackagesById: System.Runtime
  Response from https://build.server.internal/httpAuth/app/nuget/v1/FeedService.svc/FindPackagesById()?id='System.Runtime' is not a valid NuGet v2 service response.
Warning: FindPackagesById: System.Reflection
  Response from https://build.server.internal/httpAuth/app/nuget/v1/FeedService.svc/FindPackagesById()?id='System.Reflection' is not a valid NuGet v2 service response.
  GET https://build.server.internal/httpAuth/app/nuget/v1/FeedService.svc/FindPackagesById()?id='System.Reflection'
  GET https://build.server.internal/httpAuth/app/nuget/v1/FeedService.svc/FindPackagesById()?id='System.Runtime'
  GET https://build.server.internal/httpAuth/app/nuget/v1/FeedService.svc/FindPackagesById()?id='System.Diagnostics.Tracing'
Warning: FindPackagesById: System.Collections
  Response from https://build.server.internal/httpAuth/app/nuget/v1/FeedService.svc/FindPackagesById()?id='System.Collections' is not a valid NuGet v2 service response.
  GET https://build.server.internal/httpAuth/app/nuget/v1/FeedService.svc/FindPackagesById()?id='System.Collections'
Warning: FindPackagesById: System.Runtime.Extensions
  Response from https://build.server.internal/httpAuth/app/nuget/v1/FeedService.svc/FindPackagesById()?id='System.Runtime.Extensions' is not a valid NuGet v2 service response.
  GET https://build.server.internal/httpAuth/app/nuget/v1/FeedService.svc/FindPackagesById()?id='System.Runtime.Extensions'
----------
Warning: FindPackagesById: System.Diagnostics.Debug
  Response from https://build.server.internal/httpAuth/app/nuget/v1/FeedService.svc/FindPackagesById()?id='System.Diagnostics.Debug' is not a valid NuGet v2 service response.
  GET https://build.server.internal/httpAuth/app/nuget/v1/FeedService.svc/FindPackagesById()?id='System.Diagnostics.Debug'
Warning: FindPackagesById: System.Reflection
  Response from https://build.server.internal/httpAuth/app/nuget/v1/FeedService.svc/FindPackagesById()?id='System.Reflection' is not a valid NuGet v2 service response.
Warning: FindPackagesById: System.Globalization
  Response from https://build.server.internal/httpAuth/app/nuget/v1/FeedService.svc/FindPackagesById()?id='System.Globalization' is not a valid NuGet v2 service response.
Warning: FindPackagesById: System.Diagnostics.Tracing
  Response from https://build.server.internal/httpAuth/app/nuget/v1/FeedService.svc/FindPackagesById()?id='System.Diagnostics.Tracing' is not a valid NuGet v2 service response.
  GET https://build.server.internal/httpAuth/app/nuget/v1/FeedService.svc/FindPackagesById()?id='System.Diagnostics.Tracing'
  GET https://build.server.internal/httpAuth/app/nuget/v1/FeedService.svc/FindPackagesById()?id='System.Reflection'
System.IO.InvalidDataException: Response from https://build.server.internal/httpAuth/app/nuget/v1/FeedService.svc/FindPackagesById()?id='Microsoft.Owin.Host.SystemWeb' is not a valid NuGet v2 service response. ---> System.Xml.XmlException: Root element is missing.
   at System.Xml.XmlTextReaderImpl.Throw(Exception e)
   at System.Xml.XmlTextReaderImpl.ParseDocumentContent()
   at System.Xml.XmlTextReaderImpl.Read()
   at System.Xml.Linq.XDocument.Load(XmlReader reader, LoadOptions options)
   at System.Xml.Linq.XDocument.Load(Stream stream, LoadOptions options)
   at Microsoft.Framework.PackageManager.Restore.NuGet.NuGetv2Feed.EnsureValidFindPackagesResponse(Stream stream, String uri)
   --- End of inner exception stack trace ---
   at Microsoft.Framework.PackageManager.Restore.NuGet.NuGetv2Feed.EnsureValidFindPackagesResponse(Stream stream, String uri)
   at Microsoft.Framework.PackageManager.Restore.NuGet.NuGetv2Feed.<>c__DisplayClass21_0.<FindPackagesByIdAsyncCore>b__0(Stream stream)
   at Microsoft.Framework.PackageManager.Restore.NuGet.HttpSource.<GetAsync>d__8.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd(Task task)
   at Microsoft.Framework.PackageManager.Restore.NuGet.NuGetv2Feed.<FindPackagesByIdAsyncCore>d__21.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.Framework.PackageManager.RemoteWalkProvider.<FindLibrary>d__6.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.Framework.PackageManager.RestoreOperations.<FindLibrary>d__9.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd(Task task)
   at Microsoft.Framework.PackageManager.RestoreOperations.<FindLibraryByVersion>d__8.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd(Task task)
   at Microsoft.Framework.PackageManager.RestoreOperations.<FindLibraryMatch>d__6.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.Framework.PackageManager.RestoreOperations.<FindLibraryEntry>d__5.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.Framework.PackageManager.RestoreOperations.<CreateGraphNode>d__2.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd(Task task)
   at Microsoft.Framework.PackageManager.RestoreOperations.<CreateGraphNode>d__2.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.Framework.PackageManager.RestoreCommand.<CreateGraphNode>d__78.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd(Task task)
   at Microsoft.Framework.PackageManager.RestoreCommand.<RestoreForProject>d__77.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.Framework.PackageManager.RestoreCommand.<>c__DisplayClass76_0.<<Execute>b__1>d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.Framework.PackageManager.RestoreCommand.<Execute>d__76.MoveNext()
----------
Restore failed
Response from https://build.server.internal/httpAuth/app/nuget/v1/FeedService.svc/FindPackagesById()?id='Microsoft.Owin.Host.SystemWeb' is not a valid NuGet v2 service response.