The configure shell doesn't pass non-standard include directories to the
Makef ile if /usr/ucb is ahead of /usr/bin in $PATH.  /usr/ucb is an old Berkeley unix compatibility package. The problem is that /usr/ucb/tr  does handl e flags
correctly if they are two separate flag arguments.  Eg,
	/usr/ucb/tr -cd a-z
works, but 
	/usr/ucb/tr -c -d a-z
does not work as expected.  Unfortunately, in this case /usr/ucb/tr does
not print an error -- it just ignores one of the flags.  And that screws up
the configure script.

The solution is probably tohave configure or setup check that tr  works as expected, and if not,, tell the user to change their $PATH.