== _mock_ and _mach_: building Linux programs for other distributions

[[Mock http://fedoraproject.org/wiki/Projects/Mock]] and [[mach
http://thomas.apestaart.org/projects/mach/]] are both ways of building
Linux programs for other distributions. So why do you care? Simple:
they're the easiest way of building x86 binaries on an [[x86_64|]]
system.

(You would think that 'cross' compiling would be the easiest way, since
it's just building for a different ABI. Tragically, it's not, at least
not in [[Fedora Core 5 /blog/linux/FC5MissingSoSymlinks]].)

Both work by installing a complete (although usually minimal) copy of
the distribution you want to work in and _chroot()_'ing into it to do
work. [[Mock]] is very specific to building RPMs in a guaranteed clean
environment; [[mach]] is more general, and so is useful for building
arbitrary programs from source. Both are part of Fedora Extras.