I tried to follow scicalculator's instructions to brew pymol # reset if necessary (only necessary if you previsouly installed tk,tcl, or python) brew uninstall python brew uninstall tk brew uninsta ...

Read this first If you want to use Ruby/Tk (tk.rb and so on), you must have tcltklib.so which is working correctly. When you have some troubles on compiling, please read README.tcltklib and ...