Update pynac to 0.7.27 to fix wrong result on symbolic exponentiation #30446
Description
Before this ticket:
sage: n((24*sqrt(3))^(100/50))
3.80392047155301e5927962146
sage: n((24*sqrt(3))^(2))
1728.00000000000
Clearly, both should be the same, namely the second.
This was on SageMath 9.1 on openSUSE Leap 15.2 (64bit) (reported by a colleague to me).
I've tried to reproduce, but my SageMath, as well as on CoCalc crashes. The error message on my machine was
Traceback (most recent call last):
File "<string>", line 25, in <module>
ModuleNotFoundError: No module named 'Cython'
Error while executing Python code.
Saved trace to /home/dakrenn/.sage/crash_logs/crash_lqkqgydq.log
------------------------------------------------------------------------
Unhandled SIGABRT: An abort() occurred.
This probably occurred because a *compiled* module has a bug
in it and is not properly wrapped with sig_on(), sig_off().
Python will now terminate.
------------------------------------------------------------------------
Aborted (core dumped)
However, my SageMath seems to be fine otherwise, make ptestlong passes.
Same on current 9.2.beta9.
Depends on #31118
Upstream: None of the above - read trac for reasoning.
CC: @zimmermann6
Component: symbolics
Author: Ben Livingston, Dima Pasechnik
Branch: ccdf77c
Reviewer: Dima Pasechnik, Matthias Koeppe
Issue created by migration from https://trac.sagemath.org/ticket/30446