Re: config.cache considered harmful

[Lars Hecking]

Pavel Roskin writes:
> Hello, Martin!
> 
> > Let's think about when you would ever want to reuse a cache within a
> > simple single GNU package.  I claim you _never_ want to reuse that
> > config.cache file sitting in your foo-1.9 directory.  Why are you
> > re-running configure, anyways, instead of just running `make'?
> 
> Because I want to try a different _configuration_:
> 
> CFLAGS=-ggdb3 ./configure --enable-cute-feature --without-bloat
> 
> Cache really saves time when I turn on/off debugging and optional
> features. It remains valid in this case.

 Or, for instance, you have a slow machine, something like an m68040/25,
 and you update the weekly ncurses snapshot by patch. config.cache won't
 become invalid, and keeping it around for the next build helps A LOT.

 Consider the case where configure.in itself is patched, and running
 'make' will rerun autoconf AND configure.

 Or, for instance, if you're working on a package and modify configure.in
 yourself.


 Don't dump config.cache!