[poky] [PATCH] rm_work.bbclass: allow a shell var to override rm_work

[Tian, Kevin]

>From: Frans Meulenbroeks
>Sent: Sunday, December 12, 2010 11:02 PM
>
>Sometimes one is building with rm_work, but for a specific build you want to
>keep the work even if the build is successful.
>One way to achieve this is to comment the INHERIT += "rm_work" from your
>local.conf file, but this means that all recipes need to be reparsed which takes some time.
>
>This patch introduces a variable KEEP_WORK
>If this variable is set the work will not be removed.
>Intended use is
>KEEP_WORK=1 bitbake yourrecipe.bb
>Default behaviour is kept the same (in case KEEP_WORK is not set)
>
>Note that in order for this to work KEEP_WORK needs to be added to the env var
>BB_ENV_EXTRAWHITE
>e.g. export BB_ENV_EXTRAWHITE="KEEP_WORK"
>
>We still might want to improve the test so it only keeps the work if KEEP_WORK is > 0
>(or do not execute the task at all if KEEP_WORK is not set).
>Also we might want to add KEEP_WORK to the whitelist of vars that are always ok

Is it useful to further extend this KEEP_WORK option to allow task-based selection?
For example, I may only be interested on the sysroot installation path, and thus:

KEEP_WORK="install populate_sysroot" bitbake yourrecipe.bb

Currently the scope of rm_work is just binary: keep all or remove all. A finer granule
control gives us flexibility to concentrate on several tasks which most likely causes
trouble while still able to reduce the footprint.

Comment? :-)

Thanks
Kevin