Hadrian doesn't reconfigure packages upon change of Cabal Setup arguments

Say we start we start by building the default build flavour:

$ cat hadrian/UserSettings.hs
...
userFlavour :: Flavour                                                                            
userFlavour = defaultFlavour { name = "user" } -- Modify other settings here.      
...                         
$ hadrian/build.cabal.sh --flavour=user

Now we modify the build flavour adding some arguments for the Cabal Setup builder:

$ cat hadrian/UserSettings.hs
...
userFlavour :: Flavour                                                                            
userFlavour = addArgs args $ defaultFlavour { name = "user" } -- Modify other settings here.      
  where args = builder (Cabal Setup) ? arg "--disable-library-stripping"
...

Attempting to rebuild will rebuild nothing despite the change of configuration.