contrib/showstack.py

unit-tests: Fix `cargo test` on 32-bit platforms

Fixes https://bz.mercurial-scm.org/show_bug.cgi?id=6506

This makes `IndexEntryBuilder::build`, which is only used in unit tests, use
`u32` or `u64` instead of platform-dependent `usize` when packing binary data
to be used at test input.

To run Rust unit tests in 32-bit mode in a x86-64 environment, use:

    rustup target add i686-unknown-linux-gnu  # Once
    (cd rust && cargo test --target i686-unknown-linux-gnu)

Differential Revision: https://phab.mercurial-scm.org/D10351

# 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