In the course of installing some perl5 modules via pkgsrc, I've run into
the following problem: some packages still grovel your PATH in looking
for bits. (perl modules seem especially susceptible to this.)

Would it be a sane thing for pkgsrc to set an explicit and non-inclusive
PATH at configure time - something along the lines of
PATH="$LOCALBASE/bin:$LOCALBASE/sbin:$X11BASE/bin:/usr/bin:/usr/sbin:/bin:/sbin"
?