Re: Section 3.8 of the info manual not respected

[Anthony Shipman]

On Wed, 27 May 2009 11:26:14 am Philip Guenther wrote:
> On Tue, May 26, 2009 at 9:45 AM, Anthony Shipman <address@hidden> wrote:
> > I've tried the example in section 3.8 Overriding Part of Another
> > Makefile. i.e.
> >
> > foo:
> >        frobnicate > foo
> >
> > %: force
> >       address@hidden(MAKE) -f Makefile $@
> >
> > force: ;
> >
> > The command 'make foo' results in
> >
> > make[1]: Makefile: No such file or directory
> > make[1]: *** No rule to make target `Makefile'.  Stop.
> > make: *** [GNUmakefile] Error 2
>
> The paragraph just above the example says this:
> ----
>    For example, if you have a makefile called `Makefile' that says how
> to make the target `foo' (and other targets), you can write a makefile
> called `GNUmakefile' that contains:
> ----
>
> I.e., you *first* must have a file "Makefile" in the current
> directory.  The error message you got says that you don't have that,
> so of course the example doesn't work.

I expected that "make foo" would cause "frobnicate > foo" to be run and not 
require a file called Makefile to exist. I thought that the Makefile would 
only be used when a "make bar" is attempted. 

"make -d foo" says

Reading makefiles...
Reading makefile `GNUmakefile'...
Updating makefiles....
 Considering target file `GNUmakefile'.
  Looking for an implicit rule for `GNUmakefile'.
  Trying pattern rule with stem `GNUmakefile'.
  Trying rule prerequisite `force'.
  Found an implicit rule for `GNUmakefile'.
   Considering target file `force'.
    File `force' does not exist.
    Finished prerequisites of target file `force'.
   Must remake target `force'.
   Successfully remade target file `force'.
  Finished prerequisites of target file `GNUmakefile'.
  Prerequisite `force' of target `GNUmakefile' does not exist.
 Must remake target `GNUmakefile'.

So what is happening is that the match-anything rule is being used to attempt 
to update GNUmakefile. It appears to do "make -f Makefile GNUmakefile" 
without showing me that command.

So the example is correct but the error messages and debug output have 
confused me.

-- 
Anthony Shipman                    Mamas don't let your babies 
address@hidden                   grow up to be outsourced.