[gentoo-portage-dev] musings on config.{sub,guess} replacement living in econf (was: [PATCH] econf: update configure/config.{sub,guess} atomically to avoid races)

[Greg Turner]

On Tue, Dec 17, 2013 at 3:28 PM, Mike Frysinger <vapier@g.o> wrote:
> URL: https://bugs.gentoo.org/487478

Perhaps, with this bug resolved, this matter falls under the "more
trouble than its worth to fix" category -- but...

My hunch is that the decision to put the config.{sub,guess}
replacement code in econf was intended as a quick-and-dirty way to
avoid doing the replacements, in cases where no configure script runs
in an ebuild.

Post EAPI-2, the convention that hacking on the sources in "${S}"  is
a "no-no" after src_prepare has clearly crystallized considerably (I'm
guessing the code has EAPI-[01] origins); violating that convention in
econf seems awkward.

Further, the approach has a few other non-fantastic qualities:

o It doesn't run, if, for some reason, the ebuild must invoke
   configure directly rather than use econf

o when econf is invoked repeatedly, it does the same
   O(# of dirs in ${S}) noop over and over

In short... moving the config.{sub,guess} replacement code (but
probably not the shebang patching for reasons of expedience) to some
post-src_prepare place would probably be more elegant and pretty easy
to do.

As for the "only replace if we econf" issue, I can't imagine that
simply doing the replacement unconditionally would be so bad (perhaps,
with a hard-coded gnuconfig exemption, if that's needed).

Anyhow, it's very much not a big deal.  #487478 (which was entirely
theoretical, to begin with) is fixed, and there are way bigger fish to
fry in Gentoo-land... just thought I'd mention it, though, mostly as
an open note-to-self, I guess.

-gmt