Re: One-time ./configure cache file?

[Alfred M. Szmidt]

   I'm wondering if you could set up a permanent cache file for
   ./configure (like ~/.config.cache) and pass it to ./configure every
   time you build software so that it can cache answers and speed the
   process up a bit? Is this possible, and how much faster would it
   make ./configure?

Create PREFIX/etc/config.site, put something like (tweak it to your
liking):

if test "$cache_file" = ./config.cache; then
  cache_file="$prefix/var/config.cache"
  # A cache file is only valid for one C compiler.
  CC=gcc
fi

in it, and you're done.  This is noted in the manual for GNU autoconf
by the way, notably in (autoconf)Site Defaults.