Comment 8 for bug 307462

When building without --enable-pthread:
compiling tk
*****************************************************************************
**
** PTHREAD SUPPORT MODE ERROR:
**
** Ruby is not compiled with --enable-pthread, but your Tcl/Tk
** library seems to be compiled with pthread support. This
** combination may cause frequent hang or segmentation fault
** errors when Ruby/Tk is working. We recommend that you NEVER
** create the library with such a combination of pthread support.
**
** Please recompile Ruby with the "--enable-pthread" configure option
** or recompile Tcl/Tk with the "--disable-threads" configure option.
**
*****************************************************************************

So, the two options are:
(1) live with the performance penalty, keep --enable-pthread, close the bug
(2) ignore the warning (which prashant's blog recommends), and compile without --enable-pthread

We could maybe test (2) now in Ubuntu Jaunty, and see if bug reports start popping up. What do you think?