dnu restore says JSON.NET could not be found

[borgdylan]

When i restore packages i get this stack trace:

dylan@ubuntu-server:/var/www/Code/dylannet/vnext/dylan.NET.K$ dnu restore
Restoring packages for /var/www/Code/dylannet/vnext/dylan.NET.K/project.json
----------
System.IO.FileNotFoundException: Could not load file or assembly 'Newtonsoft.Json' or one of its dependencies
File name: 'Newtonsoft.Json'
  at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () <0xb41f5cc0 + 0x00035> in <filename unknown>:0 
  at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) <0xb41f4d20 + 0x000b7> in <filename unknown>:0 
  at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) <0xb41f4c90 + 0x00084> in <filename unknown>:0 
  at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) <0xb41f4c40 + 0x0003f> in <filename unknown>:0 
  at System.Runtime.CompilerServices.TaskAwaiter`1[TResult].GetResult () <0xb44e96d0 + 0x0001f> 24246 in <filename unknown>:0 
  at Microsoft.Framework.PackageManager.RestoreCommand+<>c__DisplayClass72_0+<<ExecuteCommand>b__0>d.MoveNext () <0xb39075d0 + 0x00157> in <filename unknown>:0 
--- End of stack trace from previous location where exception was thrown ---
  at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () <0xb41f5cc0 + 0x00035> in <filename unknown>:0 
  at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) <0xb41f4d20 + 0x000b7> in <filename unknown>:0 
  at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) <0xb41f4c90 + 0x00084> in <filename unknown>:0 
  at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) <0xb41f4c40 + 0x0003f> in <filename unknown>:0 
  at System.Runtime.CompilerServices.TaskAwaiter.GetResult () <0xb41f4c10 + 0x0001f> in <filename unknown>:0 
  at Microsoft.Framework.PackageManager.RestoreCommand+<ExecuteCommand>d__72.MoveNext () <0xb391b958 + 0x00787> in <filename unknown>:0 
----------
Restore failed
Could not load file or assembly 'Newtonsoft.Json' or one of its dependencies

[borgdylan]

I do not use JSON.NET in this project at all.

[muratg]

What version of dnx are you using?

cc @troydai

[troydai]

Microsoft.Framework.PackageManager still needs Newtonsoft.Json

[troydai]

@BrennanConroy hit this issue today, too. It seems to be only repo on mono

[davidfowl]

Hmm

[muratg]

@troydai Shouldn't it come transitively though?

[ChengTian]

Just want to let people know that this is under investigation.

@BrennanConroy investigated this and found the commit e9b8144 is the root cause.

@davidfowl and @BrennanConroy will do some further investigation

[davidfowl]

Ok I debugged it and figured it out. It's a behavior difference on mono with how assembly resolve works:

This is the minimal repro:

using System;
using System.Reflection;

public class Program
{
    public static void Main()
    {
        AppDomain.CurrentDomain.AssemblyResolve += (sender, e) =>
        {
            Console.WriteLine($"AssemblyResolve({e.Name})");

            Assembly.Load(new AssemblyName(e.Name));

            return null;
        };

        var an = new AssemblyName("Newtonsoft.Json, Version=6.0.0.0, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed");
        var assembly = Assembly.Load(an);
        Console.WriteLine("Hello World");
    }
}

On windows .NET this stack overflows, on mono it just fails on the second call to load. It looks like the call is cached before a result is returned from the handler. This used to work because we only passed in the short name:

Assembly.Load(PackageManager)
-> AssemblyResolve (PackageManager)
-> ImplicitLoad(Newtonsoft.Json, Version=6.0.0.0, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed)
-> AssemblyResolve(Newtonsoft.Json, Version=6.0.0.0, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed)
-> loadContext.Load(Newtonsoft.Json)
-> Call loader chain, and it works!

Notice the rename from Newtonsoft.Json, Version=6.0.0.0, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed to Newtonsoft.Json. I'll file a mono bug but also work around this in teh codez.