--- SConstruct.orig	2016-03-21 17:09:46.000000000 +0100
+++ SConstruct	2016-05-02 12:45:18.685329078 +0200
@@ -483,10 +483,10 @@ env = Environment( variables=env_vars,
                    )
 
 # Report any unknown variables as an error.
-unknown_vars = env_vars.UnknownVariables()
-if unknown_vars:
-    print "Unknown variables specified: {0}".format(", ".join(unknown_vars.keys()))
-    Exit(1)
+#unknown_vars = env_vars.UnknownVariables()
+#if unknown_vars:
+#    print "Unknown variables specified: {0}".format(", ".join(unknown_vars.keys()))
+#    Exit(1)
 
 if has_option("cache"):
     EnsureSConsVersion( 2, 3, 0 )
@@ -867,7 +867,7 @@ if nix:
     env.Append( LIBS=[] )
 
     #make scons colorgcc friendly
-    for key in ('HOME', 'TERM'):
+    for key in ('HOME', 'TERM', 'PATH', 'CCACHE_DIR'):
         try:
             env['ENV'][key] = os.environ[key]
         except KeyError: