> This is plain incorrect.  It was much, much easier to understand
> configure scripts etc before the introduction of autotools.  The
> problem is that sh is a horrible target language for a compiler, and
> M4 is a horrible implementation language for a compiler.

Yeah, it's a nasty space where you can't guarantee any tools but sh
and C. It's not a fun place to start your bootstrapping -- I'm glad
that Ruby has mkmf.rb, and extconf.rb -- for the domain of
systems-already-with-Ruby, it's far better than configure.