Re: TAP test breakage on MacOS X - Mailing list pgsql-hackers

From Noah Misch
Subject Re: TAP test breakage on MacOS X
Date
Msg-id 20141102190024.GA538247@tornado.leadboat.com
Whole thread Raw
In response to Re: TAP test breakage on MacOS X  (Noah Misch <noah@leadboat.com>)
Responses Re: TAP test breakage on MacOS X  (Peter Eisentraut <peter_e@gmx.net>)
List pgsql-hackers
On Thu, Oct 30, 2014 at 01:57:15AM -0400, Noah Misch wrote:
> On Wed, Oct 29, 2014 at 08:14:07PM -0400, Peter Eisentraut wrote:
> > On 10/28/14 9:09 PM, Peter Eisentraut wrote:
> > > I have looked into IPC::Cmd, but the documentation keeps telling me that
> > > to do anything interesting I have to have IPC::Run anyway.  I'll give it
> > > a try, though.
> > 
> > I tried this, but I'm not optimistic about it.  While parts of IPC::Cmd
> > are actually a bit nicer than IPC::Run, other parts are weird.  For
> > example, with most packages and functions in Perl that run a command,
> > you can pass the command as a string or as a list (or array reference).
> >  The latter is preferred because it avoids issues with quoting, word
> > splitting, spaces, etc.  In IPC::Run, I can use the "run" function in
> > the latter way, but I cannot use the "run_forked" function like that,
> > and I need that one to get the exit code of a command.  It's possible to
> > work around that, but I'm getting the feeling that this is not very well
> > designed.
> 
> Ick; I concur with your judgment on those aspects of the IPC::Cmd design.
> Thanks for investigating.  So, surviving options include:
> 
> 1. Require IPC::Run.
> 2. Write our own run() that reports the raw exit code.
> 3. Distill the raw exit code from the IPC::Cmd::run() error string.
> 4. Pass IPC::Run::run_forked() a subroutine that execs an argument list.

FWIW, (3) looks most promising to me.  That is to say, implement a reverse of
IPC::Cmd::_pp_child_error().  Ugly to be sure, but the wart can be small and
self-contained.



pgsql-hackers by date:

Previous
From: Petr Jelinek
Date:
Subject: Re: tracking commit timestamps
Next
From: Andrew Dunstan
Date:
Subject: Re: Let's drop two obsolete features which are bear-traps for novices