[OE-core] RFC: Separate build dir for autotools

[Burton, Ross]

On 26 February 2014 19:11, Martin Jansa <martin.jansa at gmail.com> wrote:
> Is it supposed to work correctly in incremental builds? Today I've seen
> couple of components failing in do_configure and building fine after
> manual clean, interesting part of log is that autotools.bbclass was
> actually trying to clean them:

autotools will clean away the stale build/ directory but it won't
clean ${S} sufficiently to convince configure that it can re-execute
with a different build directory.  autoconf is a bit weird here, so
sadly this means enabling B!=S for a recipe means doing a clean on
that recipe.

Unless, of course, you work out where configure is looking to bail on
this test, and if we can safely remove it on rebuilds.

Ross