SCons build tool speed

[knight at baldmt.com]

Hi Peter--

> > How does the speed of the Scons build tool compare with
> > Ant? Right now with out Ant builds take around an hour. Hoping
> > to speed that up.
>
> Don't tools like Scons, Ant, and for that matter "make" just
> execute other programs?  So that 99% of the time is consumed
> external to the Scons, Ant, or make process itself?  Why
> do you think the speed of the build tool is of any significance
> compared to the time for things like compilers and linkers
> to execute?

You're right that build times are dominated by the external commands
when rebuilds occur.  If nothing needs to be rebuilt, though, the
wall-clock time is obviously dominated by how long it takes for
the build tool to decide that.  A build tool that doesn't decide
whether or not targets are up-to-date *and* dispatch the commnds
to rebuild them reasonably quickly and efficiently doesn't do a
good job of serving its users.

        --SK