lua-pty: improved to bail out if INSTALL_CMOD is not set properly

lua/lua-pty/lpty-make-install.patch

@@ -2,7 +2,7 @@
 # This copyright note is auto-generated by ./scripts/Create-CopyPatch.
 #
 # Filename: package/.../lua-pty/lpty-make-install.patch
-# Copyright (C) 2010 The OpenSDE Project
+# Copyright (C) 2010 - 2012 The OpenSDE Project
 #
 # More information can be found in the files COPYING and README.
 #
@@ -16,18 +16,25 @@
 
 Description: Add make (un)install target and use pkg-config to find module dir
 
---- ./Makefile.orig	2010-12-01 11:09:02.134696284 +0100
-+++ ./Makefile	2010-12-01 11:23:01.934696285 +0100
-@@ -5,6 +5,8 @@
+--- ./Makefile.orig	2010-09-26 14:42:59.000000000 +0200
++++ ./Makefile		2012-04-24 13:52:54.383354702 +0200
+@@ -5,6 +5,15 @@
  LIBDIRS=-L/usr/local/lib
  LDFLAGS=-shared
  
 +INSTALL_CMOD=$(shell pkg-config --variable=INSTALL_CMOD lua)
++
++# if INSTALL_CMOD is empty we have to abort
++ifeq ($(INSTALL_CMOD), )
++$(warning Could not determine path where to install Lua C modules!)
++$(warning You need to provide the path manually by using "make INSTALL_CMOD=/path" for example.)
++$(error )
++endif
 +
  all: lpty.so
  
  lpty.so: lpty.o
-@@ -21,3 +23,9 @@
+@@ -21,3 +30,9 @@
  		rm -f $dir/.DS_Store; \
  		rm -f $dir/._*; \
  	done