contrib: add showstack extension This allows getting a Python stack trace at any time on Unix by hitting Ctrl-\ (or Ctrl-T on BSDs). Useful for debugging mysterious hangs on the fly. Sample output: $ hg log -k nosuchmessage ^\ File "/home/mpm/hg/mercurial/revset.py", line 3089, in _iterfilter if cond(x): File "/home/mpm/hg/mercurial/util.py", line 415, in f cache[arg] = func(arg) File "/home/mpm/hg/mercurial/revset.py", line 1215, in matches for t in c.files() + [c.user(), c.description()]) File "/home/mpm/hg/mercurial/context.py", line 525, in files return self._changeset[3] File "/home/mpm/hg/mercurial/util.py", line 531, in __get__ result = self.func(obj) File "/home/mpm/hg/mercurial/context.py", line 498, in _changeset return self._repo.changelog.read(self.rev()) File "/home/mpm/hg/mercurial/changelog.py", line 338, in read text = self.revision(node) File "/home/mpm/hg/mercurial/revlog.py", line 1092, in revision bins = self._chunks(chain) File "/home/mpm/hg/mercurial/revlog.py", line 1013, in _chunks ladd(decompress(buffer(data, chunkstart - offset, chunklength))) File "/home/mpm/hg/mercurial/revlog.py", line 91, in decompress return _decompress(bin) ----