Using evaluate context manager inside try clause messes things up

[Wrzlprmft]

I proceed straight to the minimal example:

from sympy import sympify, evaluate
from sympy.abc import x,y

try:
    with evaluate(False):
        sympify(")")
except:
    pass

(x+y).simplify()

This causes some obscure error in the last line that is gone when the try–except statement is removed. The error is also gone if evaluate is moved out of the try clause. While this should arguably done anyway in most cases, the error indicates that something more is going wrong.

[Eight1911]

Just out of curiosity, how did you manage to find this bug? I'm really impressed.

[Wrzlprmft]

@Eight1911: I subscribed to Stack Overflow’s SymPy tag.