Alternate source trees

[Matt Burke]

I'm trying to setup a box to do automated FreeBSD builds for other hosts
from multiple source trees.

I have a couple of source trees mounted - for legibility's sake let's say
/build/stable and /build/current. I also have a few obj dirs for different
targets. The current obj tree is symlinked to /usr/obj, and this works fine.

The problem comes when I symlink /usr/src: when I buildworld, I get
/usr/obj/build/current/[...] instead of the desired /usr/obj/usr/src/[...]
This is presumably fine when installing on the same machine, but it breaks
when using it on another host with /usr/src and /usr/obj mounted over nfs.

The only way I can see around this is a hack using a nullfs mount of
/usr/src instead of a symlink.

Am I missing something? An environment variable perhaps?

How does the build process know about the non-symlinked path anyway? I
can't see where (or understand why) it uses "pwd -P"


Thanks.