For some reason the version of tcl which we get from fedora / yum is compiled without thread safety enabled.  It's easy to download and build tcl but the default configuration is not compatible with the default version.  If I ran that program, it would not see all of the extensions that I downloaded with yum.

The instructions below show how to install tcl from sources.  This is as close as I could get to matching the original configuration.  I know that it's not exactly right.  For one thing, this version dumps some files into /usr/lib instead of /usr/lib64.  It doesn't hurt anything, aside from having an extra copy of some files.  But it does mean that you have to do the entire install, rather than just copying libtcl.so.

The .tar.gz file that I got from yum exactly matched the one available from sourceforge.  Hopefully the patch files from yum are at least close to right.

We should still install tcl from yum first, so it will satisfy all the package requirements for other packages.

yumdownloader --source tcl
su
    rpm -ivh tcl-8.5.2-2.fc9.src.rpm
** cd somwhere
tar xzvf /usr/src/redhat/SOURCES/tcl8.5.2-src.tar.gz
cd tcl8.5.2
patch -p1 < /usr/src/redhat/SOURCES/tcl-8.5.0-conf.patch
patch -p1 < /usr/src/redhat/SOURCES/tcl-8.5.1-autopath.patch
patch -p1 < /usr/src/redhat/SOURCES/tcl-8.5.0-hidden.patch
cd unix
make distclean
autoconf
./configure --enable-threads  --enable-64bit --prefix=/usr  --libdir=/usr/lib64
su
make install