Error 127 During Makeinstall of 4.8 to 4.9 Upgrade

[Bob Perry]

Hello,

I have/had FreeBSD 4.8 and was running the make installworld phase of the
upgrade to 4.9.  uname -a shows that I currently have FreeBSD
4.9-RELEASE-p2.  I came across the following error that stopped the process.

==>gnu/usr.bin/groff/font/devascii
Making R
expr: not found
***Error code 127
Stop in /usr/src/gnu/usr.bin/groff/font/devascii
***Error code 1
Stop in /usr/src/gnu/usr.bin/groff/font
***Error code 1
Stop in /usr/src/gnu/usr.bin/groff
***Error code 1
Stop in /usr/src/gnu/usr.bin
***Error code 1
Stop in /usr/src/gnu
***Error code 1
Stop in /usr/src
***Error code 1

The last code was repeated three times.
Does anyone recognize the error?  Any suggestions ?

Thanks,
Bob