trying to make tracebacks reproducible

[Faheem Mitha]

On Thu, 1 Jul 2010 20:21:48 +0200, Christian Ebert <blacktrash at gmx.net> wrote:
> Hi,
>
> Since a few days -- sorry for being vague, but this is actually
> part of the problem, I _sometimes_ get tracebacks with
> crew-stable (basically 1.6 I'd say). I cannot reproduce them
> "reliably", i.e. in the following example, I reissued the command
> and got the diff as expected. I can reduce the loaded extensions
> etc. but I'd like to reproduce this reliably first. It seems to
> happen at random - well, in the true sense of the word, if you
> look at the final lines of the traceback.

> I'd be grateful for any ideas.

The standard technique for reproducing random errors is to set the
seed, thus 'freezing' the randomness. So, try your example for
different seeds - maybe automate the seed to vary randomly, and exit
if you get an error?

                                                     Regards, Faheem.

> c
>
>
> $ hg diff -r default
> ** unknown exception encountered, details follow
> ** report bug details to http://mercurial.selenic.com/bts/
> ** or mercurial at selenic.com
> ** Python 2.6.5 (r265:79063, May 13 2010, 09:27:41) [GCC 4.0.1 (Apple Inc. build 5493)]
> ** Mercurial Distributed SCM (version 1.5.4+190-521c8e0c93bf)
> ** Extensions loaded: keyword, mq, convert, patchbomb, graphlog, record, extdiff, color, pager, crecord
> Traceback (most recent call last):
>   File "/usr/local/bin/hg", line 27, in <module>
>     mercurial.dispatch.run()
>   File "/usr/local/lib/python2.6/site-packages/mercurial/dispatch.py", line 16, in run
>     sys.exit(dispatch(sys.argv[1:]))
>   File "/usr/local/lib/python2.6/site-packages/mercurial/dispatch.py", line 34, in dispatch
>     return _runcatch(u, args)
>   File "/usr/local/lib/python2.6/site-packages/mercurial/dispatch.py", line 54, in _runcatch
>     return _dispatch(ui, args)
>   File "/usr/local/lib/python2.6/site-packages/mercurial/dispatch.py", line 483, in _dispatch
>     cmdpats, cmdoptions)
>   File "/usr/local/lib/python2.6/site-packages/mercurial/dispatch.py", line 351, in runcommand
>     ret = _runcommand(ui, options, cmd, d)
>   File "/usr/local/lib/python2.6/site-packages/mercurial/extensions.py", line 160, in wrap
>     return wrapper(origfn, *args, **kwargs)
>   File "/usr/local/lib/python2.6/site-packages/hgext/pager.py", line 95, in pagecmd
>     return orig(ui, options, cmd, cmdfunc)
>   File "/usr/local/lib/python2.6/site-packages/mercurial/extensions.py", line 160, in wrap
>     return wrapper(origfn, *args, **kwargs)
>   File "/usr/local/lib/python2.6/site-packages/hgext/color.py", line 213, in colorcmd
>     return orig(ui_, opts, cmd, cmdfunc)
>   File "/usr/local/lib/python2.6/site-packages/mercurial/dispatch.py", line 534, in _runcommand
>     return checkargs()
>   File "/usr/local/lib/python2.6/site-packages/mercurial/dispatch.py", line 488, in checkargs
>     return cmdfunc()
>   File "/usr/local/lib/python2.6/site-packages/mercurial/dispatch.py", line 481, in <lambda>
>     d = lambda: util.checksignature(func)(ui, *args, **cmdoptions)
>   File "/usr/local/lib/python2.6/site-packages/mercurial/util.py", line 408, in check
>     return func(*args, **kwargs)
>   File "/usr/local/lib/python2.6/site-packages/mercurial/extensions.py", line 116, in wrap
>     util.checksignature(origfn), *args, **kwargs)
>   File "/usr/local/lib/python2.6/site-packages/mercurial/util.py", line 408, in check
>     return func(*args, **kwargs)
>   File "/usr/local/lib/python2.6/site-packages/hgext/mq.py", line 2791, in mqcommand
>     return orig(ui, repo, *args, **kwargs)
>   File "/usr/local/lib/python2.6/site-packages/mercurial/util.py", line 408, in check
>     return func(*args, **kwargs)
>   File "/usr/local/lib/python2.6/site-packages/mercurial/commands.py", line 1452, in diff
>     cmdutil.diffordiffstat(ui, repo, diffopts, node1, node2, m, stat=stat)
>   File "/usr/local/lib/python2.6/site-packages/mercurial/cmdutil.py", line 677, in diffordiffstat
>     changes, diffopts):
>   File "/usr/local/lib/python2.6/site-packages/mercurial/patch.py", line 1492, in difflabel
>     for chunk in func(*args, **kw):
>   File "/usr/local/lib/python2.6/site-packages/mercurial/patch.py", line 1449, in diff
>     changes = repo.status(ctx1, ctx2, match=match)
>   File "/usr/local/lib/python2.6/site-packages/mercurial/localrepo.py", line 1088, in status
>     mf2.set(f, ctx2.flags(f))
>   File "/usr/local/lib/python2.6/site-packages/mercurial/context.py", line 737, in flags
>     flag = findflag(self._parents[0])
>   File "/usr/local/lib/python2.6/site-packages/mercurial/context.py", line 731, in findflag
>     ff = self._repo.dirstate.flagfunc(lambda x: flag or '')
>   File "/usr/local/lib/python2.6/site-packages/mercurial/dirstate.py", line 131, in flagfunc
>     if self._checklink:
>   File "/usr/local/lib/python2.6/site-packages/mercurial/util.py", line 163, in __get__
>     result = self.func(obj)
>   File "/usr/local/lib/python2.6/site-packages/mercurial/dirstate.py", line 115, in _checklink
>     return util.checklink(self._root)
>   File "/usr/local/lib/python2.6/site-packages/mercurial/util.py", line 697, in checklink
>     name = tempfile.mktemp(dir=path, prefix='hg-checklink-')
>   File "/usr/local/lib/python2.6/site-packages/mercurial/demandimport.py", line 75, in __getattribute__
>     self._load()
>   File "/usr/local/lib/python2.6/site-packages/mercurial/demandimport.py", line 47, in _load
>     mod = _origimport(head, globals, locals)
>   File "/sw/lib/python2.6/tempfile.py", line 34, in <module>
>     from random import Random as _Random
>   File "/usr/local/lib/python2.6/site-packages/mercurial/demandimport.py", line 106, in _demandimport
>     mod = _origimport(name, globals, locals)
>   File "/sw/lib/python2.6/random.py", line 59, in <module>
>     LOG4 = _log(4.0)
> ValueError: math domain error
>