RE: [PATCH] Makefile: add and use the ".DELETE_ON_ERROR" flag

Ævar Arnfjörð Bjarmason wrote:

As in db10fc6c09f this allows us to remove patterns of removing
leftover $@ files at the start of rules, since previous failing runs
of the Makefile won't have left those littered around anymore.

I'm not as confident that we should be replacing the "mv $@+ $@"
pattern entirely, since that means that external programs or one of
our other Makefiles might race and get partial content.

The reason I did it in db10fc6c09 is because both asciidoctor and
asciidoc should deal with temporary files by themselves (like gcc). If
you interrupt the build nothing gets generated.

However, other scripts like build-docdep.perl would indeed generate
partial output.

In my opinion it's the scripts themselves that should be fixed, and not
the Makefile, *if* we care about this at all.

-- 
Felipe Contreras