The emulators/qemu package does not build on NetBSD-current (i386):

    /usr/pkgsrc/emulators/qemu $ make
    ERROR: qemu-0.8.1nb2 cannot use gcc-4.1.2
    *** Error code 1

Is there some way to force pkgsrc to use an older compiler version
from pkgsrc instead?  I worked around the issue in my own pkgsrc tree
by setting

    GCC_REQD+=              3.4
    USE_PKGSRC_GCC=         yes

in emulators/qemu/Makefile, but I don't see any other packages setting
USE_PKGSRC_GCC in the Makefile, so I figure that's not the correct
solution.  Setting just GCC_REQD doesn't help.

Actually fixing qemu work with gcc4 is nontrivial; according to the
QEMU FAQ gcc4 is "incompatible with the way qemu handles dynamic
translation".
-- 
Andreas Gustafsson, gson@gson.org