[Python-ideas] Rewriting the build system (part 2)

[Stephen J. Turnbull]

Ryan Gonzalez writes:

 > I have used fbuild a LOT

Actually, I suspect that in the relevant sense, you haven't used it a
lot.  Have you used it for a single program on

1.  more than 3 CPUs, AND
2.  on each CPU, more than one (and preferably more than two) OSes, AND
3.  for each CPU-OS combination, more than two different configurations
    of the program being built, AND
4.  for each CPU-OS-configuration combination, at least 3 versions of
    the program source (preferably spanning a major version bump)?

The number of programs/versions you have built on a single (or small
selection of) CPU-OS combinations is irrelevant to the discussion.
The problem autotools helps to solve better than any other system I
know of is bootstrapping on a new system.  It's also quite good at
handling foibles (== regressions) across version bumps of the source
program.

I agree it's suboptimal (at best :-) to have a PyPI module that
depends on the autotools.  I've found it to be a real PITA for Windows
users who want to develop certain Emacs Lisp applications, for
example, which is a similar kind of development environment to Python.

But for bootstrapping Python itself, what else is there, really?
Every time I've seen a project move to something like SCons, I've also
seen their port rate to new platforms decrease dramatically.  (Hard to
interpret that trend, though -- if a project has the free cycles to
change build systems, maybe they have ported to almost all of the
plausible platforms already.)  Autotools alternatives just have way
fewer modules for dealing with new and/or old ;-) platforms.

Bright! Shiny! New! system         use crufty old system :-(
           +                  =>              +
   missing library :-(                     library

Caveat: Autotools is the only build system (well, Imake -- now you
know how old I am!) I have substantial experience with.  But I've
heard stories from colleagues about the limitations of Scons and
cmake in this respect, and I find it hard to believe that there are
systems out there with the accumulated knowledge of platforms that has
been assembled in Autotools over the decades.