[OE-core] [PATCH 1/1] combo-layer-tool: add tool to manipulate combo layers

[Paul Eggleton]

On Thursday 28 July 2011 13:11:00 Koen Kooi wrote:
> I've been playing with this script and I have a few remarks about it. First
> the ones that aren't the fault of the script:
> 
> 1) overlapping files like .gitignore breaks the script

This can be a problem, yes. However if you know about these sorts of conflicts 
ahead of time you can mitigate them by adding the appropriate logic to a hook 
script (which can filter out stuff from the patches as they pass through).

> 2) git format-patch | git am is a lossy process, so you can't import
> oe-core and bitbake from scratch:
> 
> 	[14:08:48] Apply
> /Users/koen/Projects/Angstrom/setup-scripts/sources/combo-layer/patch-d99a
> aa2f-57f3-4c07-aac3-afc0538cae88/bitbake/0020-codeparser.py-Ignore-incomple
> te-cache-files.patch [14:08:48] Applying: codeparser.py: Ignore incomplete
> cache files error: patch failed: bitbake/lib/bb/codeparser.py:75
> 	error: bitbake/lib/bb/codeparser.py: patch does not apply
> 	Patch failed at 0001 codeparser.py: Ignore incomplete cache files
> 	When you have resolved this problem run "git am --resolved".
> 	If you would prefer to skip this patch, instead run "git am --skip".
> 	To restore the original branch and stop patching run "git am --abort".

Perhaps I'm being thick, but what's the reason for this failing?
 
> 3) rotating disks are slow when trying to apply a few thousand patches

I think this is kind of the fault of the script in that it's the default 
behaviour - frankly I never expected anyone to use combo-layer to build a 
combined repo from scratch dragging across the entire history. Ideally you 
would begin from an existing repository that you had manually combined 
together, and combo-layer is the way of keeping it up-to-date after that 
point. We could easily automate the initial creation within the script if 
people think it's useful - I did think about doing that but I figured it's not 
something you expect to do very often.

> As for the script I only have one real complaint: The inability to set
> branches so you can make a combo layer based on non-master (e.g. release)
> branches.

Agreed, this is an omission, shouldn't be too difficult to fix though. It's on my 
todo list, feel free to submit a patch if you want it fixed faster ;)

Cheers,
Paul

-- 

Paul Eggleton
Intel Open Source Technology Centre