I've narrowed a typing failure down to the following snippet:

# pyright: reportUnusedVariable=true

def f(a: int):
    b = {}
    c = a
    used = 1
    for _ in range(1):
        if a:
            pass
        if 0:
            b[c].append(0)
        c = used if 1 else 0

f(0)

With pyright==1.1.401, this yields: error: Variable "used" is not accessed.

This seems incorrect - if I remove used = 1, then this crashes with NameError: name 'used' is not defined.