./configure finds the path to the python interpretter and its associated module directory, and this information is . As part of the gmenu-simple-editor.in -> gmenu-simple-editor processing, the module directory is patched in via @pyexecdir@, but the path to the python interp is left up to a runtime `env python`. That means the python used as runtime, "first 'python' in PATH" might not be the one against which the gnome-menus python bindings were compiled. Even if I explicitly pass PYTHON when running configure "use this specific python interp", `env python` is still being used instead.