[OE-core] proper way to bounce between two (or more) build directories?

[Robert P. J. Day]

On Thu, 22 Mar 2012, Scott Garman wrote:

> On 03/22/2012 04:42 AM, Robert P. J. Day wrote:
> >
> >    haven't seen this mentioned anywhere and i know it's simple but
> > i want to confirm this.
> >
> >    say i run oe-init-build-env to initialize a new project, part
> > of the effect of that is to prepend the OE and bitbake related
> > directories to PATH.  i work there for a while, then want to put
> > that on hold to start a second build.
> >
> >    i rerun oe-init-build-env to set up that second build, which
> > works fine but, unsurprisingly, that prepends the OE directories
> > to my PATH *again* (but i really have no choice, it has to be
> > done).
> >
> >    after a while, i want to go back to the first project.  am i
> > expected to run oe-init-build-env yet again?  (prepending
> > directories yet again?)
>
> I would generally do my best to avoid working with multiple build
> areas in the same terminal, and it's definitely not a case we test
> with.

  i had assumed as much, but i was curious to know the actual
difference in the working environment between two builds.  sometimes
info like that is educational.

> >    as best i can tell, the only change i need to make in switching
> > build directories is to reset the BUILDDIR env variable.  is that
> > all that's necessary?  i don't see anything else in my environment
> > that would have to be reset.
>
> Compare your env before and after running the oe-init-build-env
> script, then prepend something to unset the variables that were
> added.

  i did and the only meaningful differences were (as i suspected):

  * BUILDDIR is updated
  * PATH kept being prepended unnecessarily with OE/bitbake dirs

> If you want to submit a patch make the oe-init-build-env script
> idempotent in this way, that could be useful.

  the only thing that i can suggest is that that script check if PATH
already contains the OE dirs at the front, and not prepend them again,
but that's obviously not a big deal.

rday

-- 

========================================================================
Robert P. J. Day                                 Ottawa, Ontario, CANADA
                        http://crashcourse.ca

Twitter:                                       http://twitter.com/rpjday
LinkedIn:                               http://ca.linkedin.com/in/rpjday
========================================================================