Hi Paul,
Paul Smith wrote:
> > If I compare the configure output from a run with using the cache
> > (fails) with one that doesn't use the cache (succeeds) the only
> > difference of interest is:
>
> -checking for sigprocmask... (cached) 1
> +checking for sigprocmask... yes
> ...
> -checking for sigprocmask... (cached) 1
> +checking for sigprocmask... yes
The situation with the Autoconf cache is not pretty: The documentation
merely states how the caching works, but
- neither when and how the 'configure' user is meant to use it,
- nor how an Autoconf macro should be written for good interoperation
with the cache.
More than 15 years ago, I heard "the autoconf cache is broken". As I
realized that the cache's contents depend on
- the package you are compiling,
- the version of a .m4 file with an autoconf macro,
- the values of $CC and $CFLAGS (even '-m32' vs. '-m64'),
I stopped using it (except for collecting known values for cross-
compilation).
If you think that certain uses of the Autoconf cache can be made to
work reliably, please go ahead and document in the Autoconf manual
- what these uses are,
- what an Autoconf macro author should do for it to work.
Bruno
