Well, doing repo -diff and apply produced patch when I newly repo sync could work.


https://groups.google.com/forum/#!topic/repo-discuss/43juvD1qGIQ


________________________________
From: Takashi Matsuzawa
Sent: Monday, January 30, 2017 11:00 AM
To: yocto@yoctoproject.org
Subject: patching .bbclass files?


Hello Yocto
I am curious if there is a better way of doing this manually every time I re-synch to Yocto based BSP.

Say, I have a patch or customization I want to try on .bbclass files (instead of .bb or .bbappend, or the source files that are fetched.)
The reason for this is sometimes I want to try the latest fix to the BSP while building old versino of my image, or debbuging image by modifying the build system files.

I think by using .bbappend files I can try modification to the .bb file behaviros, but it does not for .bbclass files.
I could add slightly modified xxx.bbclass to my own layer so that it may override what is available in poky/meta/..., but it may mean I just duplicate a lot of bitbake related files in my layer for just a few lines of changes.

'repo' having a feature copying files when repositories are synched.  This may work for me?

Ideally, the poky and other remote gits have branches or releases that have the patches I want to try, or I should be using the latest releases that should include meaningful fixes already.
But it is not possible always.