To compile 'tcltklib', you must have Tcl/Tk libraries on your environment. Although 'extconf.rb' script searches Tcl/Tk libraries and header files, sometimes fails to find them. And then, 'tcltklib' cannot be compiled. If Tcl/Tk libraries or header files are installed but are not found, you can give the information by arguments of the 'configure' script. Please give some or all of the following options. --with-tcllib= (e.g. libtcl8.4.so ==> --with-tcllib=tcl8.4) --with-tklib= (e.g. libtk8.4.so ==> --with-tklib=tk8.4) --enable-tcltk_stubs (if you force to enable stubs) --with-tcl-dir= equal to "--with-tcl-include=/include --with-tcl-lib=/lib" --with-tk-dir= equal to "--with-tk-include=/include --with-tk-lib=/lib" --with-tcl-include= the directry containts 'tcl.h' --with-tk-include= the directry containts 'tk.h' --with-tcl-lib= the directry containts 'libtcl.so' --with-tk-lib= the directry containts 'libtk.so' --enable-mac-tcltk-framework (Mac OSX only) use Tcl/Tk framework If you forgot to give the options when do 'configure' on toplevel directry of Ruby sources, please try something like as the followings. $ cd ext/tcltklib $ rm Makefile $ CONFIGURE_ARGS='--with-tcl-include=/usr/local/include/tcl8.4/ --with-tcllib=tcl8.4 --with-tklib=tk8.4' ruby extconf.rb *** ATTENTION *** When your Tcl/Tk libraries are compiled with "pthread support", Ruby/Tk may cause "Hang-up" or "Segmentation Fault" frequently. If you have such a trouble, please try to use the '--enable-pthread' option of the 'configure' command and re-compile Ruby sources. It may help you to avoid this trouble. The following configure options may be useful. --enable-tcl-thread/--disable-tcl-thread --with-tclConfig-file= It is not need that 'tclConfig.sh' is a normal Tcl/Tk's tclConfig.sh. But the file is expected to include the line "TCL_THREADS=0" or "...=1". When no "TCL_THREADS=?" line, if Tcl version is 7.x or 8.0 which is given by "TCL_MAJOR_VERSION=?" line and "TCL_MINOR_VERSION=?" line, then --disable-tcl-thread is expected. Else, ignore the 'tclConfig.sh'. If --enable-tcl-thread or --disable-tcl-thread option is given, then --with-tclConfig-file option is ignored. ========================================================== Hidetoshi NAGAI (nagai@ai.kyutech.ac.jp)