Uninitialized attribute _a1 in base_attr_nullable_int_alt1::Foo::run (alt/base_attr_nullable_int_alt1.nit:32)
,---- Stack trace -- - -  -
| base_attr_nullable_int_alt1::Foo::run (alt/base_attr_nullable_int_alt1.nit:30)
| base_attr_nullable_int_alt1::Foo::init (alt/base_attr_nullable_int_alt1.nit:42)
| base_attr_nullable_int_alt1::Sys::main (alt/base_attr_nullable_int_alt1.nit:75)
`------------------- - -  -