quickly build a single program ?

[Giorgos Keramidas]

On Sat, 24 Jan 2009 00:36:11 +0100, Luigi Rizzo <rizzo at iet.unipi.it> wrote:
> how hard would it be to modify the build scripts so that they only try
> to rebuild a single program from a tree where you already made a buildworld ?
>
> i usually do modifications to a single program at a time and it is
> slightly annoying to wait for the build process to scan through all
> the already-built programs to find there is nothing to do for them.

Most of the time, when there are small changes I just change into the
program's directory and `make'.   But this doesn't work when there are
dependencies with other parts of buildworld.

> I guess one would have to override SUBDIR in the main Makefile.inc1,
> and then again in the children Makefiles, taking each time the next
> component of the filename...

Overriding SUBDIR might be a bit hard to do `right' when there are
libraries or header files involved.  For example libexec/sendmail
depends on stuff from contrib/ but rebuilding *only* the final
`sendmail' binary may not work if it links with a stable static library
like libsm.a from the OBJDIR.

But it sounds like an interesting thing :)