./configure -C

[Andy Wingo <wingo pobox com>]

Hello all,

Brian Gough wrote, back in February [0]:

  In his talk about Autotools at the FOSDEM GNU Dev Room, Ralf
  Wildenheus mentioned an autoconf option that I wasn’t aware of. It’s
  the “-C” option and it enables caching, which speeds up multiple runs
  of a ./configure script enormously.

  $ ./configure --help
       --cache-file=FILE   cache test results in FILE [disabled]
   -C, --config-cache      alias for `--cache-file=config.cache'
  $ ./configure -C
  configure: loading cache config.cache
  ...

  Caching used to be the default up to about 10 years ago, but was
  turned off as the cache gets out of sync with the system if new
  packages are installed. Also it really only benefits developers, as
  end-users typically only need to run ./configure once.

  In the 1990′s I got used to caching being enabled by default and when
  it was turned off I never noticed the change — except that somehow
  running ./configure while developing seemed a lot slower in the past
  ten years!

  Thanks to Ralf for pointing out this option as I am now using -C all
  the time.

[0] http://blogs.fsfe.org/bjg/2011/02/autoconf-caching-an-option-i-didnt-know-about/

It came to my attention that some GTK+ folks were not aware of this, as
I wasn't, before seeing Ralf's presentation.  See
http://www.gnu.org/s/hello/manual/autoconf/Cache-Files.html for more
info.  I think you'll find that when hacking on your projects, it's
quite useful!

Cheers,

Andy
-- 
http://wingolog.org/