CI builds randomly fail when restoring Roslyn

[eerhardt]

Here's an example:

https://ci.dot.net/job/dotnet_source-build/job/dev_release_2.0/job/RHEL7.2_Release_prtest/69/consoleText

When restoring for

/mnt/resource/j/workspace/dotnet_source-build/dev_release_2.0/RHEL7.2_Release_prtest/Tools/dotnetcli/dotnet restore /mnt/resource/j/workspace/dotnet_source-build/dev_release_2.0/RHEL7.2_Release_prtest/src/roslyn/CLI.sln

First we get a bunch of "retrying" messages that look like:

Retrying 'FindPackagesByIdAsync' for source 'https://www.myget.org/F/vs-devcore/api/v3/flatcontainer/runtime.unix.system.diagnostics.debug/index.json'.
    An error occurred while sending the request.
      Couldn't connect to server
    Retrying 'FindPackagesByIdAsync' for source 'https://www.myget.org/F/vs-devcore/api/v3/flatcontainer/runtime.osx.10.10-x64.runtime.native.system/index.json'.
    An error occurred while sending the request.
      Couldn't connect to server
    Retrying 'FindPackagesByIdAsync' for source 'https://www.myget.org/F/vs-devcore/api/v3/flatcontainer/runtime.unix.system.io.filesystem/index.json'.
    An error occurred while sending the request.
      Couldn't connect to server

Which eventually fails with:

/mnt/resource/j/workspace/dotnet_source-build/dev_release_2.0/RHEL7.2_Release_prtest/Tools/dotnetcli/sdk/2.0.0-preview3-006845/NuGet.targets(102,5): error : Failed to retrieve information about 'runtime.osx.10.10-x64.runtime.native.System.Net.Http' from remote source 'https://www.myget.org/F/vs-devcore/api/v3/flatcontainer/runtime.osx.10.10-x64.runtime.native.system.net.http/index.json'. [/mnt/resource/j/workspace/dotnet_source-build/dev_release_2.0/RHEL7.2_Release_prtest/src/roslyn/CLI.sln] [/mnt/resource/j/workspace/dotnet_source-build/dev_release_2.0/RHEL7.2_Release_prtest/targets/repository.proj]

Which then breaks the build.

We should investigate the issue. At a minimum we need to do something to make our builds pass more often than they fail.

The current suggestion is to add --disable-parallel to see if it helps with the reliability issue.

[tannergooding]

@agocke, do you recall why we added --disable-parallel originally (looks like you are the one who added the option)?

[dleeapho]

This was fixed by @eerhardt right?

[eerhardt]

I added a temporary workaround so this was no longer blocking us. But @jaredpar and @tannergooding should still work with the NuGet team to understand the underlying issue here. And, if possible, provide a real fix for the issue.

[crummel]

This is NuGet issue NuGet/Home#4538, closing on our side.