[Build-common-hackers] Teaching people about CDBS

[Emilio Pozuelo Monfort]

On 16/04/11 00:23, Jonas Smedegaard wrote:
> Hi [again] Phil,
> 
> On 11-04-15 at 10:34pm, Philip Hands wrote:
>> [This is a repost of a mail that was originally sent privately to 
>>  Jonas, which he asked me to post here to then provide him the chance 
>>  to give his helpful reply a wider airing -- I hope you all find it 
>>  useful]
>>
>> Hi Jonas,
>>
>> I hope you're well.
> 
> Thanks, I am.  And reading this letter helps too :-D
> 
> It just occurs to me that my image of you is "...with a smile".  I 
> actually never recall having seen you not happy.  So I just assume you 
> ae well too ;-)
> 
> 
>> I'm giving a tutorial on Debian package building in May[1], and while 
>> it might be tempting to allow my bigotry to win, and just say "Don't 
>> use CDBS" I don't think that is really the right thing to do, 
>> especially since I'm sure that some of the attendees will be wanting 
>> to know about packaging because they want to be able to apply local 
>> patches, which means they're very likely to need to patch CDBS based 
>> packages at some point.
>>
>> Also, from your recent comments about CDBS, it seems that I ought to 
>> have another look at it, since it sounds like it's changed quite a lot 
>> since I developed my bigotry ;-)
> 
> Thanks a lot for the kind words.  Quite encouraging!
> 
> 
>> So, that being the case, I was wondering if you could point me at good 
>> example packages that demonstrate CDBS's strengths, or illustrate why 
>> one might want to prefer CDBS over dh7.  Also, if there's and good 
>> intro that you could suggest, that would be great too.
> 
> to take that last thing first: Documentation is shitty. Flat out.  We 
> are working on improving that, but nothing concrete yet.
> 
> I generally try to tidy all packages that I am involved in packaging, so 
> ideally you should be able to pick from any of the 200+ packages here: 
> http://qa.debian.org/developer.php?login=Smedegaard&comaint=yes
> 
> In reality, however, there is obviously ones more polished than others.
> 
> Just today I noticed the following changelog entry in pango1.0:
> 
>    * Switch to CDBS with its awesome flavors support.
> 
> ...so perhaps grab that package as example.  Flavored builds are one of 
> the recent features of CDBS, here needed to compile udebs specially 
> AFAIK.  The pango1.0 package also nicely (more so than my common 
> packaging style) uses make variables and expansions, which IMO is the 
> core argument for CDBS over short-form dh: The ddebian/rules file is a 
> make file and CDBS extends on that instead of reinventing make (e.g. 
> graphing algorithms for dependency chaining of build tasks) in Perl.

I was going to suggest that you look at pango1.0, gtk+3.0 or glib2.0 for
packages using CDBS' flavored build support (I switched all them :) ). You may
want to show how they were before using CDBS (you can grab packages from
snapshot.debian.org) and then when they were ported.

About all my packages are CDBS ones too. See pkg-gnome ones (sources are in svn)
if you want more examples.

Cheers,
Emilio