DNX always chooses the highest framework

[Kieranties]

Scenario: I have a console application that may be ran in both dnx451 and dnx46

When running dnx . run the application is always ran as a dnx46 application. In the code base there has been an explicit decision to always run against the highest discovered framework version:

dnx/src/dnx.clr.managed/DomainManager.cs

Line 97 in 90d2bdb

// Find the highest DNX desktop version, if any and map it to .NET version

Why is that? Would it be possible to provide a flag to dnx when executing for the target framework (e.g. dnx . run -fw dnx451)

Trivial example:

/* project.json */
{
  "userSecretsId": "aspnet5-ConsoleApp1-20150724092501",
  "version": "1.0.0-*",
  "description": "ConsoleApp1 Console Application",
  "authors": [ "kieranties" ],
  "tags": [ "" ],
  "projectUrl": "",
  "licenseUrl": "",

  "dependencies": {
    "Microsoft.Framework.Runtime.Abstractions": "1.0.0-beta6-*"
  },

  "commands": {
    "ConsoleApp1": "ConsoleApp1"
  },

  "frameworks": {
    "dnx46": { },
    "dnx451": { }
  }
}

/* Program.cs */
using Microsoft.Framework.Runtime;
using System;

namespace ConsoleApp1
{
    public class Program
    {
        private readonly IApplicationEnvironment _appEnv;

        public Program(IApplicationEnvironment appEnv)
        {
            _appEnv = appEnv;
        }

        public void Main(string[] args)
        {
            Console.WriteLine(_appEnv.RuntimeFramework);
            Console.WriteLine(_appEnv.ApplicationBasePath);
#if DNX46
            Console.WriteLine(AppContext.BaseDirectory);
#endif
        }
    }
}

/* Current result */
> dnx . run
DNX,Version=v4.6
C:\dump\x\ClassLibrary1\src\ConsoleApp1
C:\Users\kieranties\.dnx\runtimes\dnx-clr-win-x86.1.0.0-beta6-12231\bin\

[davidfowl]

This is actually part of the intended design. You should be able to pass in the framework for quirking and compilation on the command line but we would prefer the highest in the absence of that information.

/cc @anurse

[Kieranties]

@davidfowl It's still to do then?

[davidfowl]

Yes

[Kieranties]

Super!

[davidfowl]

/cc @muratg this needs to go into beta7

[moozzyk]

Related to #1970. We need to find a way passing arguments (this, DNX_DEFAULTLIB, OS, architecture) to the app domain manager without using environment variables.