contrib/showstack.py

packaging: add dependencies to the PyOxidizer build on macOS

Otherwise, we get a bunch of test failures for missing things like pygments, or
tests skipped entirely.  The input file is a copy/paste from the equivalent
Windows file, but with dulwich, pygit2, and pytest-vcr commented out because
the build process errors out with them, flagging them as incompatible with
loading from memory.  I have no idea if that's actually true or not, because
I've noticed that if I don't `make clean` after every build, the next build
flags the watchman stuff as incompatible with loading from memory.

The remaining failures are:

    Failed test-alias.t: output changed
    Failed test-basic.t: output changed
    Failed test-check-help.t: output changed
    Failed test-commit-interactive.t: output changed
    Failed test-extension.t: output changed
    Failed test-help.t: output changed
    Failed test-i18n.t: output changed
    Failed test-log.t: output changed
    Failed test-qrecord.t: output changed
    Failed test-share-safe.t: output changed

Most of the issues seem related to loading help for disabled extensions from
`hgext.__index__`, namely the full extension help being unavailable, not being
able to resolve what commands are provided by what extension, and not having the
command level help available.

test-log.t, test-commit-interactive.t, and test-i18n.t look like i18n (or lack
thereof) issues.

test-basic.t is just odd:
    @@ -55,7 +55,7 @@
     On Python 3, stdio may be None:

       $ hg debuguiprompt --config ui.interactive=true 0<&-
    -   abort: Bad file descriptor (no-rhg !)
    +   abort: response expected
        abort: response expected (rhg !)
       [255]
       $ hg version -q 0<&-

# 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)
"""

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