[oe] [OE-core] [RFC][PATCH] cmake: respect ${S} and ${B}

[Burton, Ross]

On 5 December 2013 09:47, Stefan Herbrechtsmeier
<stefan at herbrechtsmeier.net> wrote:
> I think deleting ${B} before building is wrong. If the build directory makes
> problem you should have the same problems when ${S} and ${B} are same or you
> should remove the ${B} directories when you remove the build files from
> ${S}.

Yes, without S!=B there are problems, and the solution is to put B in
a separate directory and delete the old one when starting a build.
Removing the build files from ${S} is "non-trivial", running "make
clean" isn't universal, and even for autotools distclean isn't always
enough.

oe-core has this as opt-in behaviour for as many modules as possible
and it makes switching machines so much nicer, as you don't get
modules using the previous sysroot.  libproxy does this on demand
currently, and anything using libtool will also have this problem.

Ross