I have installed ruby 1.6.7 on two computers using Red Hat 8.0 Linux.
This installs tcl in usr rather than usr/local.  I want to use the Tk
extension.

On one computer the make for Ruby does not compile tcltklib. It seems to
just pass over it.  The log from make goes

compiling tcltklib
compiling tk

and it then compiles tkutil.c and makes tkutil.so but does not touch
tcltklib.

On the other installation it does make tcltklib.so.  The only difference
I can identify is that the second computer had Red Hat 8 as an upgrade
from RH 7.2, and the first computer has it as a new installation.

Is there anything I can do to force make to build tcltklib?

Thank you

John Fletcher