[Bf-committers] New Developer Meeting minutes

[Campbell Barton]

The build system topic took most of the meeting or so and I hope we
dont let this happen again or the new dev meetings will get very
uninteresting.
Please next time try to avoid arguing about stupid topics like this
while we are trying to give basic info to new devs.

I think topics like this just need better WIKI Docs and not discussion
with new devs. (Or limit to 5min intro)
----
Hi Nathan, I didnt mean to say scons does full rebuilds, just that its
slower if you do quick rebuilds.
SCons is great to get a build running however for development Im now
quite convinced its not the way to go.

When nothing needs building, CMake's Makefiles take around 2.1 seconds
on my system. Scons takes between 30 and 40 seconds.
Time to compile and link with one change with CMake made is 6.8 second or so.
I have tried optimizing scons before and I can get moderate
speedups... but it still doesnt get close to CMake's.

SCons with BF_QUICK gives more acceptable times but this means I waste
time thinking about what libs to build and occasionally getting it
wrong and having to find out why BF_QUICK failed.

I appreciate your work on scons and dont mean to belittle it but with
CMake so much faster for rebuilds I feel justified in recommending
CMake over scons for people who intend to build often.

- Campbell

On Thu, Jan 7, 2010 at 8:46 AM, Nathan Letwory <jesterking at letwory.net> wrote:
> Roger Wickes wrote:
>>
>> We held our second monthly new developer meeting(http://wiki.blender.org/index.php/Dev:SundayMeetingAgenda/NewDev_meetings)
>> on Sunday, attracting x new developers to the Blender family.
>> Minutes are here: http://wiki.blender.org/index.php/Dev:SundayMeetingAgenda/NewDev_meetings/2010-01-03rd.
>> We discussed Build systems, Patch Submission, and Python, with a focus on Cmake versus Scons.
>
> Hi, great to see that the second new dev meeting has been held - too bad
> I couldn't be there, since SCons has been talked about, too.
>
> I feel I have to make a small comment though:
>
> SCons never does a full recompile, when it is not necessary (and it
> hardly ever is). So in that sense, SCons will also do incremental
> builds. Sure, it does read in the SConscripts, but *that is not
> equivalent to a complete rebuild*. It does pose some slight overhead
> when starting a build, but that should not be the reason to start
> favoring CMake over SCons. Again: SCons builds only what is needed.
>
> When doing a clean rebuild, (remove *everything* created by SCons/CMake
> before doing your build), I assure you that you won't find useful
> differences in build times.
>
> I have started writing out docs on the SCons system on my blog
> http://www.letworyinteractive.com/b/building-blender-with-scons/ (see
> also the top navigation for more links). More info there will gradually
> be published as I get it all written out. It already contains good info
> on how the configuration of the system goes.
>
> /Nathan
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-- 
- Campbell