------------------------------ PROGRAM OUTPUT ------------------------------ Output from '/usr/local/bin/perl5.13.10 Makefile.PL': no display name and no $DISPLAY environment variable while executing "load /usr/lib/libtk8.4.so.0 Tk" ("package ifneeded" script) invoked from within "package require Tk" (file "test-for-tk.tcl" line 1) Your Tcl installation (tclsh) fails to find Tk package.