Environment

Computer 1:

• Pythonnet version: 2.3, installed via pip I think
• Python version: 2.7.12
• Operating System: Ubuntu 16.04.2

Computer 2:

• Pythonnet version: manual build on master from commit ce14424 (currently 11 commits behind)
• Python version: 2.7.12
• Operating System: Ubuntu 16.04.2

Details

Description: Python calls .NET function which returns a List. Python then passes the return value, without modification, to a second .NET function which accepts a List. Computer 1 executes this code just fine. On Computer 2, there is no .NET function found that matches the arguments because the return value of the .NET function has been transformed into a Python list.

Python code:

import clr
from MyDotNetProject import PythonInterop

x = PythonInterop.GetDoubleList()
PythonInterop.PrintDoubleList(x)

.NET code:

    public class PythonInterop
    {
        public static List<Double> GetDoubleList() {
            var result = new List<Double>();
            result.Add(1);
            result.Add(2);
            result.Add(3);
            return result;
        }

        public static void PrintDoubleList(List<Double> list) {
            Console.WriteLine("You list has " + list.Count + " elements");
        }
    }

The Python code works fine on Computer 1. On Computer 2, the PrintDoubleList call produces
TypeError: No method matches given arguments

If I print type(x) in Python, Computer 1 gives me a .NET List type while Computer 2 gives me a Python list. I can print x.Count on Computer 1, but I get a missing attribute error on Computer 2.

If I build manually from the 2.3 tag, I get the same (good) behavior as on Computer 1.

It seems that some feature has been partially added to automatically convert .NET objects into Python objects when possible. I suppose this is ok (though I would prefer that not happen because I don't want the mandatory performance hit of converting even when I don't want to convert), but if that's the intention, there must be automatic conversion of Python objects to .NET objects also. One without the other is a critical bug.