i686-pc-sco3.2v5.0.4-gcc can't find cpp

[Gary Ashton-Jones <gaj at austaxprac dot com dot au>]

I followed the README for egcs-1.1b and ran './configure', 'make' and
then 'make install'. All seemed OK but when I started to compile mySQL I
got an error abort and when I checked the log I found this:

configure:3877: gcc -belf -o conftest -O3 -g -O2 -DDBUG_OFF   conftest.c
-lm  -lcrypt -lgen  -lgthreads -lsocket -lgthreads 1>&5
gcc: installation problem, cannot exec `cpp': No such file or directory
gcc: file path prefix `/usr/local/lib/gcc-lib/elf/egcs-2.91.57/' never
used

The error message is correct. There is no directory
'/usr/local/lib/gcc-lib/elf/egcs-2.91.57/'. The closest I could find
was:
/usr/local/lib/gcc-lib/i686-pc-sco3.2v5.0.4/egcs-2.91.57/ which contains
cpp

How do I make gcc look in the correct directory? (Is this a mySQL
problem or a gcc problem?)

PS How do I run the testsuite on gcc? I can't find any mention of it in
README, INSTALL or Makefile.

TIA

Gary