Not sure if this is an issue with wrapt or abc. The following code will raise a TypeError: issubclass() arg 1 must be a class instead of printing True as I would expect:

import wrapt
import abc

class Base(abc.ABC):
    pass

@wrapt.decorator
def pass_through(wrapped, instance, args, kwargs):
    return wrapped(*args, **kwargs)

@pass_through
class Klass(Base):
    pass

print(issubclass(Klass, Base))

Apparently, abc.ABC replaces the subclasscheck with its own special subclasscheck, which in turn raises the exception. Unfortunately, that subclasscheck is some internal function that I cannot debug. The last arguments for this internal subclasscheck that the debugger can see are <class '__main__.Base'> and <class '__main__.Klass'>, which looks fine to me.

The example above can be simplified even further to

import wrapt
import abc

@wrapt.decorator
def pass_through(wrapped, instance, args, kwargs):
    return wrapped(*args, **kwargs)

@pass_through
class Klass(abc.ABC):
    pass

print(issubclass(Klass, abc.ABC))

but I chose the first example because it demonstrates better what I want to achieve.