Wrong binding of closure variable with intervening list comprehension

[limwz01]

Bug report

Bug description:

def f(x):
    def g():
        print([x for x in range(10)])
        def h():
            print(x)
        return h
    print(x)
    return g
f(1)()()

The above had always bound x in h to the parameter of f. But it no longer works and somehow binds to a local in g, throwing the following error:

NameError: cannot access free variable 'x' where it is not associated with a value in enclosing scope

CPython versions tested on:

3.12

Operating systems tested on:

Linux, Windows

Linked PRs

• gh-121377: Fix closure with intervening comprehension #124696

[gaogaotiantian]

This is probably related to PEP 709 @carljm .

[carljm]

I've just moved house and am behind on everything, so it may be a bit before I can get to this, but I will fix it.

[limwz01]

@carljm any updates?

[carljm]

I'm intending to work on this during the upcoming core dev sprint in September. If someone else gets to it first that's fine, though!