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Date:   Wed, 28 Feb 2018 07:42:51 +0000
From:   Eric Wong <e@80x24.org>
To:     Jeff King <peff@peff.net>
Cc:     Jonathan Nieder <jrnieder@gmail.com>,
        "Randall S. Becker" <rsbecker@nexbridge.com>, git@vger.kernel.org,
        'Joachim Schmitz' <jojo@schmitz-digital.de>,
        =?utf-8?B?w4Z2YXIgQXJuZmrDtnLDsA==?= Bjarmason <avarab@gmail.com>
Subject: Re: [Problem] test_must_fail makes possibly questionable assumptions
 about exit_code.
Message-ID: <20180228074251.GA11673@dcvr>
References: <005501d3b025$c0057ce0$401076a0$@nexbridge.com>
 <20180228001616.GJ174036@aiede.svl.corp.google.com>
 <20180228040718.GA9043@whir>
 <20180228050034.GA373@sigill.intra.peff.net>
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Jeff King <peff@peff.net> wrote:
> On Wed, Feb 28, 2018 at 04:07:18AM +0000, Eric Wong wrote:
> 
> > > In the rest of git, die() makes a command exit with status 128.  The
> > > trouble here is that our code in Perl is assuming the same meaning for
> > > die() but using perl's die builtin instead.  That suggests a few
> > > options:
> > > 
> > >  a) We could override the meaning of die() in Git.pm.  This feels
> > >     ugly but if it works, it would be a very small patch.
> > 
> > Unlikely to work since I think we use eval {} to trap exceptions
> > from die.
> > 
> > >  b) We could forbid use of die() and use some git_die() instead (but
> > >     with a better name) for our own error handling.
> > 
> > Call sites may be dual-use: "die" can either be caught by an
> > eval or used to show an error message to the user.

<snip>

> > >  d) We could wrap each command in an eval {...} block to convert the
> > >     result from die() to exit 128.
> > 
> > I prefer option d)
> 
> FWIW, I agree with all of that. You can do (d) without an enclosing eval
> block by just hooking the __DIE__ handler, like:
> 
> $SIG{__DIE__} = sub {
>   print STDERR "fatal: @_\n";
>   exit 128;
> };

Looks like it has the same problems I pointed out with a) and b).