Re: [PATCH 1/r47] maint: help2man targets should rely on the binaries they call.

[Ralf Wildenhues]

Hi Eric,

* Eric Blake wrote on Wed, Sep 22, 2010 at 07:37:58PM CEST:
> On 09/22/2010 11:35 AM, Ralf Wildenhues wrote:
> >* Gary V. Vaughan wrote on Wed, Sep 22, 2010 at 07:05:48PM CEST:
> >>* Makefile.am (doc/libtool.1, doc/libtoolize.1): Don't rely on
> >>the intermediate files, since they might have changed without
> >>giving make the opportunity to update the actual binaries that
> >>help2man calls in time.
> >
> >No, because 'libtool' is created in the build tree, and the manpages are
> >distributed.  Distributed files may not depend on undistributed files,
> >as that breaks building from a read-only source tree.  Moreover,
> >help2man is something the user is expected to not have to install prior
> >to building Libtool.
> 
> Is it acceptable instead to use a nested $(MAKE) invocation prior to
> running help2man to ensure the binary is up-to-date?

Can you show a patch so I can see what you mean?

There are differences in semantics between GNU and some non-GNU make
implementations in the way that some of the latter may always consider
some prerequisite updated if they invoked the rule for updating the
prerequisite.  I'm hoping these makes die out, but we aren't quite there
yet.

Cheers,
Ralf