[poky] ccache

[Bob Cochran]

On 04/03/2012 01:36 PM, Chris Larson wrote:
> On Tue, Apr 3, 2012 at 10:31 AM, Gary Thomas<gary at mlbassoc.com>  wrote:
>> Why is ccache being used for Poky/Yocto builds?  My understanding is
>> that it's a win for _rebuilds_ of the same/related files, but there's
>> not a whole lot of that going on.
>>
>> If I build core-image-sato from scratch, I end up with ${BUILD}/tmp/ccache
>> which is 1.8GB - quite a bite!  Is there some way to disable this?, other
>> than not have ccache on my host computer (not an option as it is useful
>> for other builds I do)
>
> I think the default behavior of using ccache when it's installed is
> extremely bad, and dangerous, in that the ccache object cache is of
> both limited usefulness, as you say, and the object cache can get
> corrupted, leading to extremely odd behavior (and it's rarely a place
> you think to look as a cause). At Mentor we disabled this behavior,
> and I really, really think we should do so in the default oe-core
> bitbake.conf.


It would be nice / cleaner to not build out the hollow ccache directory 
structure under tmp when ccache isn't installed or being used.  Seeing 
it there under tmp with levels of empty sub directories beneath it is 
somewhat confusing.