Merged requested to merge bitbucket/merged-pr-238 into branch/release-2.3.x
Created originally on Bitbucket by kostialopuhin (Konstantin Lopukhin)
Was already merged in Bitbucket before import, marked as merged by the import user
Without this fix, running pypy/tool/release/package.py failed to compile tkinter support (could not find X11 headers). But I am not quite sure that this fix is generic enough.