Build only changes

[Konstantin Belousov]

On Mon, Nov 30, 2015 at 06:56:01PM +0600, Alexander Kuleshov wrote:
> Hello Slawa,
> 
> On Mon, Nov 30, 2015 at 6:09 PM, Slawa Olhovchenkov <slw at zxy.spb.ru> wrote:
> >
> > May be `make buildworld -DNO_CLEAN` is enough?
> >
> > For some dirs I am do direct build. For other this is not work.
> 
> Thank you for reply, but anyway it's too long to wait. Would great to have
> options for skipping contrib/, usr.bin/ and other non-related to
> changes directories,
> but unfortunately didn't see it in Makefiles.

If you already finished buildworld, it is usually easiest and fastest
to execute make buildenv with the same options as buildworld (I mean
things like TARGET/TARGET_ARCH and similar), then, in the shell prompt,
do
# cd usr.bin/program
# make

I use this when working e.g. on rtld and libc/libthr.  A useful variation
is
# make DEBUG_FLAGS=-g WITHOUT_TESTS=yes