Re: dummy prerequisites and "make clean"

[John Darrington]

On Thu, Nov 19, 2020 at 10:31:28PM -0800, Ben Pfaff wrote:
     When I type "make clean", the first thing that happens is that gnulib
     gets built. This seems to be caused by commit 49501a8888003350 "Add
     default to generate prerequisistes for any rule", which always build
     libgl, even if the target is "clean".
     

It should only do that if libgl is not up to date.


     I don't understand the goal of
     that commit; the commit message isn't clear to me.
     Maybe the goal is to build the BUILT_SOURCES and libgl.la even when
     some more specific target is provided to "make". I don't think that's
     possible without this kind of problem cropping up.


Yes.  Before this commit, attempting to run many targets from a clean tarball
without first running "make" (from memory, I think "make check", "make doc" and
"make install" were just some of those affected), resulted in wierd failures 
after
about five minutes half way through the process.

Having this default target ensures that these prerequisites are up-to-date 
before
doing *anything*.   I can understand that it's annoying in the case of "make 
clean".
(I usually use "git clean -dfx" for cleaning)

J'