Re: updating target at the end of recipe, after updating prerequisites, might not work?

[David Boyce]

On Wed, Oct 5, 2011 at 6:45 PM, Mark Galeck (CW) <address@hidden> wrote:
> How can this be???  Even if the resolution was low enough that the two files 
> have the _same_ timestamp, according to the manual, should not update the 
> target (only update the target if prerequisites "newer").  Certainly there is 
> no way the prerequisites can be "newer".
>
> Can somebody clue me in?

I cannot reproduce this on Ubuntu 11.04. Using the following makefile:

% cat Makefile
tgt: prq1 prq2
        touch $^
        touch $@

The right thing happens reliably. Note that you can use the "stat"
program to see mtimes down to the microsecond. When I do this all 3
files have the same [acm]time, and as noted make does the right thing.
Ubuntu 11 still uses make 3.81.

-David Boyce