[yocto] Is the build system SCM sensitive?

[Gary Thomas]

On 2014-10-27 12:03, Saul Wold wrote:
> On 10/27/2014 09:50 AM, Gary Thomas wrote:
>> I had a complete build (details probably don't matter) using
>> Poky master.  I'm working on a fix to one of the core recipes,
>> so I made a local branch:
>>    % git checkout -b fix-python-pygtk master
>> I made a single line change in the recipe (removing a line from
>> the do_install step).  When I then rebuilt the recipe, to my
>> surprise, there were more than 450 tasks (73 unique recipes)
>> executed :-(
>>
>> How does this make any sense?  unless the build system cares
>> that I changed the branch?
>>
>> n.b. I'm happy to provide more details if necessary.  Also, I
>> did this twice in two different build trees and saw the same
>> strangeness.
>>
> I think so additional info might be needed here, I am guessing that you are changing pygtk and somehow that is changing some dependency, you might try using bitbake-diffsigs
> between the 2 versions.

I think I know what triggered this - a recent change in bitbake.conf
redefined BUILD_CPP (and others).  I had merged this change some six
hours before my strange build and had been building many other recipes
(also python with a similar set of dependencies) a number of times
before I touched the python-pygtk recipe.  Some dependency in that
recipe set off the rebuild storm that my other recipes had not.

So the large number of recipe rebuilds was [probably] warranted, but
very unexpected given what I had been doing just prior.

Sorry for the noise.  Next time I'll try and remember bitbake-diffsigs
and figure things out on my own.

-- 
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Gary Thomas                 |  Consulting for the
MLB Associates              |    Embedded world
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