fix PWD

Author: bbbradsmith

makefile.wx

@@ -65,8 +65,8 @@ wxlib: submodules
 	(cd $(WXOUT)/$(WXCMAKE) && cmake --build .)
 	(cd $(WXOUT)/$(WXCMAKE) && cmake --install . --prefix ..)
 	(cd $(WXOUT)/$(WXCMAKE) && echo '#!/bin/sh' > wx-config-install)
-	(cd $(WXOUT)/$(WXCMAKE) && echo "this_prefix=\"$PWD/..\"" >> wx-config-install)
-	(cd $(WXOUT)/$(WXCMAKE) && echo "this_exec_prefix=\"$PWD/..\"" >> wx-config-install)
+	(cd $(WXOUT)/$(WXCMAKE) && echo "this_prefix=\"$(shell PWD)/..\"" >> wx-config-install)
+	(cd $(WXOUT)/$(WXCMAKE) && echo "this_exec_prefix=\"$(shell PWD)/..\"" >> wx-config-install)
 	(cd $(WXOUT)/$(WXCMAKE) && tail -n 2 wx-config | sed "s/\/lib\/wx\/config\//\/..\/$(WXCMAKE)\/lib\/wx\/config\//g" >> wx-config-install)
 	(cd $(WXOUT)/$(WXCMAKE) && chmod +x wx-config-install)