I found if you bootstrap the pkgsrc with gcc, things seems compiling better. So here is the basics. (On a standard 6.3.2
 installation)

1) you still need the  pkgsrc_qnxutil-0.14.tar.gz, in the project download area. Download it and install it.

2) I would suggest use gcc 3.3.5 instead of 2.95.3, unfortunatly there seems no default way to do it other than re-link 
the binaries. I wrote a little script myself, which is attached.

3) make sure you cleaned up everything. /usr/pkg/; /var/db; if there is "work" directory left in package directory, 
better remove them first.

4) cd bootstrap; ./cleanup; ./bootstrap

Don't need any option.

Try build some packages with bmake.