set TRACING_ON one way or another explicitly in the

SConscript file instead of basing it on DEBUG

--HG--
extra : convert_revision : 6e6807cc4350ef92baeaaabfeb3dc0bb785128ba

src/SConscript

@@ -316,16 +316,17 @@ else:
 
 makeEnv('debug', '.do',
         CCFLAGS = Split('%s -O0' % debug_flag),
-        CPPDEFINES = 'DEBUG')
+        CPPDEFINES = ['DEBUG', 'TRACING_ON=1'])
 
 # Optimized binary
 makeEnv('opt', '.o',
-        CCFLAGS = Split('-g -O3'))
+        CCFLAGS = Split('-g -O3'),
+        CPPDEFINES = ['TRACING_ON=1'])
 
 # "Fast" binary
 makeEnv('fast', '.fo', strip = True,
         CCFLAGS = Split('-O3'),
-        CPPDEFINES = 'NDEBUG')
+        CPPDEFINES = ['NDEBUG', 'TRACING_ON=0'])
 
 # Profiled binary
 makeEnv('prof', '.po',