[Buildbot-devel] Incorporating environment settings into a factory

[Greg Ward]

On Jan 23, 2008 8:32 PM, Richard Offer <offer at fastscale.com> wrote:
> Thanks for the idea Ben, I'm still unclear how buildbot is architected.
>
> Does it build its commands to be executed once when it parses the file or when the steps are
> executed ?

Generally speaking, the former.  Your master.cfg is just a Python
program that is subject to the same rules as any other Python program,
which is to say "the sane sensible rules that any programming language
ought to use".  (If that doesn't help, the semantics for variable
evaluation, function calls, etc. are broadly similar to those for both
Java and JavaScript.  Alas, programming languages that consistently
use sane and sensible rules are few and far between.)

If you want delayed evaluation, you can get it, but you have to want
it: either write your own BuildStep (e.g. by subclassing ShellCommand)
or use WithProperties.  See section 6.1.4.4 "Build Properties" of the
User Manual for Buildbot 0.7.6
(http://buildbot.net/repos/release/docs/buildbot.html) for details.

Greg