bug#12123:

[Eli Zaretskii]

> Date: Fri, 05 Apr 2013 23:47:28 -0700
> From: Paul Eggert <eggert@cs.ucla.edu>
> CC: chad <yandros@MIT.EDU>, 12123@debbugs.gnu.org
> 
> On 04/05/2013 10:48 AM, Eli Zaretskii wrote:
> > Perhaps Paul (CC'ed) could import it and
> > use it in callproc.c to do what Stefan suggested.
> 
> That sounds like it might work, yes, but it's
> nontrivial.  I've never used that module myself.

Then perhaps we could just borrow the ideas from progreloc.c.