Repeating the default WARNS here makes it slightly more difficult to
experiment with default WARNS changes, e.g. if we did something absolutely
bananas and introduced a WARNS=7 and wanted to try lifting the default to
that.
Drop most of them; there is one in the blake2 kernel module, but I suspect
it should be dropped -- the default WARNS in the rest of the build doesn't
currently apply to kernel modules, and I haven't put too much thought into
whether it makes sense to make it so.
Just like bin/ and sbin/, I think setting WARNS to the highest value
possible will make it more attractive for people to fix warnings.
- The WARNS variable is set in the Makefile in the directory of the
application itself, making it more likely that it will be removed out
of curiosity to see what happens.
- New applications will most likely build with WARNS=6 out of the box,
because the author would more likely fix the warnings during
development than lower WARNS.
Unfortunately almost all apps in libexec require a lowered value of
WARNS.
