0.5 is mostly a bugfixes release but also has very important changes to option defaults.

Manual setup is now the default

In other words, it means that the autosetup option is set to False by default (instead of True in version 0.4).

If you don't want to use autosetup anymore (this is the recommended approach), you need to call (if you are not doing it already):

setup_all()

once after all your entities (classes) have been defined (and before using them).

If you still want to use autosetup (this is not recommended), you need to set the option one way or another: either by adding using_options(autosetup=True) to all your entities or by adding elixir.options_defaults['autosetup'] = True before any of your entities are defined.

See Migrate03to04#AutomaticVSmanualsetup or TutorialDivingIn04#a3.Action for more exlanation about what autosetup and setup_all do.

Inheritance is polymorphic by default

This means, that those who want to use polymorphic inheritance, don't need to set the polymorphic option on their entities anymore (whether through using_options or through elixir.options_defaults). It also means that those who don't want polymorphic inheritance now need to specify that by using either: using_options(polymorphic=False) in all their entities part of the "inheritance chain" or elixir.options_defaults['polymorphic'] = False before any of their entity is declared.