Re: Autoconf/Automake is not using version from AC_INIT

[Bob Friesenhahn]

On Mon, 25 Jan 2021, Peter Johansson wrote:

> Hi Bob,
>
> On 24/1/21 10:06 am, Bob Friesenhahn wrote:
> > I did try this type of solution.  As I recall, it did not help because the 
> > terminal target is Automake's regeneration rules, which are apparently 
> > optimized to not modify the target files (e.g. configure) if there was no 
> > change.
>
> This seems like a very annoying optimization. IIUC, that means if I'd touch 
> the timestamp of 'configure.ac' without changing its content, I'd end up in 
> this hole of 'configure.ac' being newer than 'configure' but 'configure' not 
> being updated. That doesn't seem to be the case in one of my projects. If I 
> just 'touch configure.ac && make' all downstream files are updated as 
> expected (except 'config.h', which is a known behavior), so I suspect you 
> have something else going with the dependencies. Impossible to guess what 
> without seeing the relevant Makefile snippet.

The key part of the simplified solution is (was) this:

AC_SUBST([CONFIGURE_DEPENDENCIES],["$CONFIGURE_DEPENDENCIES \$(top_srcdir)/ChangeLog 
\$(top_srcdir)/version.sh"])

Although these are declared as "dependencies", if one of them changed 
it did not necessarily result in configure being updated.  If the 
information provided to AC_INIT was the same as before it did not seem 
to result in configure being updated.

Bob
--
Bob Friesenhahn
bfriesen@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer,    http://www.GraphicsMagick.org/
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