Repository navigation
Passing Python objects implementing a generic C# interface to a C# method fails in 3.0.0 #1982
Description
Environment
- Pythonnet version: 2.5.2 and 3.0.0.post01
- Python version: 3.7.6 (2.5.2) and 3.9.12 (3.0.0.post01)
- Operating System: Win10
- .NET Runtime: .NET 6
Details
Passing a Python object (obj) that implements a generic interface in Python (ISome) to a C# class fails in pythonnet 3.0 but works in 2.5.2; same behaviour whether specific (SomeSpecific) or generic (SomeGeneric)
- What commands did you run to trigger this issue? If you can provide a
Minimal, Complete, and Verifiable example
this will help us understand the issue.
namespace Some.Namespace
{
public interface ISome<T1>
{
public T1 Get1(T1 x);
}
public class SomeSpecific
{
public SomeSpecific(ISome<int> some, int x)
{
Console.Out.WriteLine($"Spec1 = {some.Get1(x)}");
}
}
public class SomeGeneric<T1>
{
public SomeGeneric(ISome<T1> some, T1 x)
{
Console.Out.WriteLine($"Gen1 = {some.Get1(x)}");
}
}
}from Some.Namespace import ISome, SomeGeneric, SomeSpecific
class PySome(ISome[int]):
__namespace__ = 'Some.Namespace'
def Get1(self, x):
return x
obj = PySome()
print(obj.Get1(4))
# Next two lines fail in 3.0.0
SomeSpecific(obj, 4)
SomeGeneric[int](obj, 4)- If there was a crash, please include the traceback here.
Traceback (most recent call last):
SomeSpecific(obj, 4)
System.ArgumentException: Cannot resolve method Int32 Get1(Int32) because the declaring type of the method handle Some.Namespace.ISome`1[T1] is generic. Explicitly provide the declaring type to GetMethodFromHandle.
at System.Reflection.MethodBase.GetMethodFromHandle(RuntimeMethodHandle handle)
at Python.Runtime.PythonDerivedType.MarshalByRefsBack(Object[] args, RuntimeMethodHandle methodHandle, PyObject pyResult, Int32 outsOffset) in /tmp/build-via-sdist-rlpexh5w/pythonnet-3.0.0.post1/src/runtime/Types/ClassDerived.cs:line 844
at Python.Runtime.PythonDerivedType.InvokeMethod[T](IPythonDerivedType obj, String methodName, String origMethodName, Object[] args, RuntimeMethodHandle methodHandle) in /tmp/build-via-sdist-rlpexh5w/pythonnet-3.0.0.post1/src/runtime/Types/ClassDerived.cs:line 727
at Some.Namespace.PySome.Get1(Int32 )
at Some.Namespace.SomeSpecific..ctor(ISome`1 some, Int32 x) in
Activity
filmor commentedon Nov 2, 2022
Thank you for the detailed report and reproducible example.
This is a regression due to #1663, I'll try to fix the generated code.
filmor commentedon Nov 2, 2022
Fixed in #1998, I'll cut a release tomorrow.