view contrib/showstack.py @ 44120:35cd52c4a5cc

py3: conditionalize test-flagprocessor.t on Python 3.8

For reasons I don't understand, Python 3.8 is outputting a different
lint in the traceback than prior Pythons.

The lines in question are:

    flagutil.addflagprocessor(
        REVIDX_NOOP, (noopdonothingread, noopdonothing, validatehash,)
    )

Python <3.8 prints the 2nd line but 3.8 the first line. Perhaps Python
changed its traceback logic to always print the first line of a
multiple line expression?

Whatever the case, with this change, the test now passes on
Python 3.8.

Differential Revision: https://phab.mercurial-scm.org/D7945

# showstack.py - extension to dump a Python stack trace on signal
#
# binds to both SIGQUIT (Ctrl-\) and SIGINFO (Ctrl-T on BSDs)
r"""dump stack trace when receiving SIGQUIT (Ctrl-\) or SIGINFO (Ctrl-T on BSDs)
"""

from __future__ import absolute_import, print_function
import signal
import sys
import traceback


def sigshow(*args):
    sys.stderr.write("\n")
    traceback.print_stack(args[1], limit=10, file=sys.stderr)
    sys.stderr.write("----\n")


def sigexit(*args):
    sigshow(*args)
    print('alarm!')
    sys.exit(1)


def extsetup(ui):
    signal.signal(signal.SIGQUIT, sigshow)
    signal.signal(signal.SIGALRM, sigexit)
    try:
        signal.signal(signal.SIGINFO, sigshow)
    except AttributeError:
        pass