Gentoo's Bugzilla –
Attachment 317298 Details for
Bug 424916dev-lang/python-2.7.3 - In file included from /var/tmp/portage/dev-lang/python-2.7.3/work/Python-2.7.3/Modules/_tkinter.c:67:0: /usr/include/tk.h:21:3: error: #error Tk 8.5 must be compiled with tcl.h from Tcl 8.5