--- SConstruct.orig
+++ SConstruct
@@ -745,8 +745,7 @@
 
 if nix:
     env.Append( CPPFLAGS="-fPIC -fno-strict-aliasing -ggdb -pthread -Wall -Wsign-compare -Wno-unknown-pragmas -Winvalid-pch" )
-    if linux:
-        env.Append( CPPFLAGS=" -Werror " )
+    env.Append( CXXFLAGS=os.environ['CXXFLAGS'])
     env.Append( CXXFLAGS=" -Wnon-virtual-dtor " )
     env.Append( LINKFLAGS=" -fPIC -pthread -rdynamic" )
     env.Append( LIBS=[] )
@@ -757,8 +756,6 @@
     if debugBuild:
         env.Append( CPPFLAGS=" -O0 -fstack-protector " );
         env['ENV']['GLIBCXX_FORCE_NEW'] = 1; # play nice with valgrind
-    else:
-        env.Append( CPPFLAGS=" -O3" )
 
     if debugLogging:
         env.Append( CPPFLAGS=" -D_DEBUG" );