Re: About ./configure --cache-file (WAS: CHECK_STRUCTS/dmpstruct.h mechanism is broken.)

[Daniel Colascione]

On 4/13/19 7:44 PM, Paul Eggert wrote:
> Noam Postavsky wrote:
> > The cache is not invalidated automatically, so you need to delete it
> > after upgrading devel libraries or compiler.
>
> ... or if you configure with different flags, or if you edit 
> configure.ac or if you do a bunch of other things. For the kind of work 
> I do, the cache is way more trouble than it's worth.

The caching could probably be a lot better. We could incorporate a hash 
of the passed-in variables and of the environment into the cache file 
now. As for changing configure.ac itself: that's very rare. I also 
wonder CC="ccache gcc" might help even for the case of a 
frequently-changed configure.ac.