diff -ur mypaint-1.0.0.orig/mypaint.py mypaint-1.0.0/mypaint.py
--- mypaint-1.0.0.orig/mypaint.py	2011-11-22 21:27:03.000000000 +0100
+++ mypaint-1.0.0/mypaint.py	2012-09-26 16:21:40.125539307 +0200
@@ -68,6 +68,9 @@
 
     if os.path.basename(dir_install) == 'bin':
         prefix=os.path.dirname(dir_install)
+        if prefix == "/":
+            # we have most likely a usrmoved system and disallow a prefix of /
+            prefix = u"/usr"
         assert isinstance(prefix, unicode)
         libpath=join(prefix, lib_shared)
         libpath_compiled = join(prefix, lib_compiled)