Fix problem with devtool and BBCLASSEXTENDed recipes

Is no one using devtool with BBCLASSEXTENDed recipes? Because when I tried that today I noticed that after having done "devtool modify -x foo-native" the recipe would not rebuild after having changed the source code (the way it does for non-native recipes).

As far as I can tell the problem is that externalsrc.bbclass sets BB_DONT_CACHE inside an anonymous Python function after having checked if EXTERNALSRC is set. However, for BBCLASSEXTENDed recipes BB_DONT_CACHE needs to be set for the base recipe rather than the current variant. Why this is, I have no idea.

First I thought of unconditionally setting BB_DONT_CACHE in the externalsrc bbclass, but then I realized that people may be used to, e.g., inherit externalsrc in their local.conf and that would effectively cause every recipe to be reparsed every time bitbake is executed...

Eventually I managed to implement a solution that seems to work and only sets BB_DONT_CACHE as necessary. It may not be kosher as it looks at overridden variants of EXTERNALSRC, but it was the best I could come up with.

I know too little of the recipe parsing internals to be able to tell whether the current behavior is working as intended or if it is a bug that BB_DONT_CACHE must be set for the base recipe. I leave that for someone more knowledgeable in the parsing internals to investigate.

//Peter

The following changes since commit 5414b80e8df11188d8e67a37185305c34ea084bd:

bitbake: cooker: check if target contains task (2016-09-16 15:24:03 +0100)

are available in the git repository at:

git://git.yoctoproject.org/poky-contrib pkj/externalsrc_dont_cache
http://git.yoctoproject.org/cgit.cgi/poky-contrib/log/?h=pkj/externalsrc_dont_cache

Peter Kjellerstedt (1):
externalsrc.bbclass: Make reparsing work for BBCLASSEXTENDed recipes

 meta/classes/externalsrc.bbclass | 20 +++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

2.9.0