Email bug reports to bug-sourceinstall@gnu.org, trying to be as clear and precise as possible. This means that you should provide all useful information that could help to identify the problem, and a detailed way to reproduce it. A good starting point is to specify your OS name and version. If you have no idea about what OS you have, try:
$ uname -a
Also, if you can please specify your tcl, tk, and expect versions.
If your problem regards GNU Source Installer installation, more information is needed: please read the sections “Installing the Installer” and “Troubleshooting Installation”.