Makefile macros - dependency to shell

[jerzy szczudłowski]

I've already sent that question to users list, but it's still
unanswered, so trying here.

I've lost whole afternoon trying to figure out why I can't install
NVidia drivers (using nvidia-installer). Finally I found that their
Makefile uses macro "$(PWD)", which is not being set if make is run
under ksh (aka default PLD root shell). Illustration below:

#v+
# cat Makefile                       
install:
         echo "$(PWD)"

# make
echo ""

# bash
# make
echo "/root"
/root
#v-

Is that a bug in Makefile? (should that macro have been defined
explicitly?) Or is it bug in pdksh?