Using a cache file by default

[Niels Möller]

Hi,

I'm having a project with a few subdirectories with their own
configure(.in) scripts. Using a shared cache file saves a lot of time,
even on the first run of configure, since the different configure
scripts often tests for the same things.

So with recent versions of autoconf I have to remember to add the -C
option. However, I don't always run coinfigure manually. In
particular, automake's distcheck target tars up all the code, unpacks
it in a fresh directory, and runs configure. It doesn't use -C (and I
don't quite feel like hacking automake to change that).

So I'd wish there were some environment variable I could set that a
configure script (generated by a recent autoconf) looks at, to get it
to use a cache file by default, just like it used to do... Is there
anything like that?

Regards,
/Niels