Tests failing on macOS

[hoodie]

I think 27e6bade might have introduced some brackage on macOS - at least I can not compile fn test_hash_order() on macOS (linux works fine🤷🏼‍♂️). What I see is the following:

error[E0308]: mismatched types
   --> src/yaml.rs:623:9
    |
623 |         assert_eq!(Some((Yaml::String("b".to_owned()), Yaml::Null)), iter.next());
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected enum `yaml::Yaml`, found &yaml::Yaml
    |
    = note: expected type `std::option::Option<(yaml::Yaml, yaml::Yaml)>`
               found type `std::option::Option<(&yaml::Yaml, &yaml::Yaml)>`
    = help: here are some functions which might fulfill your needs:
            - .take()
            - .unwrap()
    = note: this error originates in a macro outside of the current crate

error[E0308]: mismatched types
   --> src/yaml.rs:624:9
    |
624 |         assert_eq!(Some((Yaml::String("a".to_owned()), Yaml::Null)), iter.next());
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected enum `yaml::Yaml`, found &yaml::Yaml
    |
    = note: expected type `std::option::Option<(yaml::Yaml, yaml::Yaml)>`
               found type `std::option::Option<(&yaml::Yaml, &yaml::Yaml)>`
    = help: here are some functions which might fulfill your needs:
            - .take()
            - .unwrap()
    = note: this error originates in a macro outside of the current crate

error[E0308]: mismatched types
   --> src/yaml.rs:625:9
    |
625 |         assert_eq!(Some((Yaml::String("c".to_owned()), Yaml::Null)), iter.next());
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected enum `yaml::Yaml`, found &yaml::Yaml
    |
    = note: expected type `std::option::Option<(yaml::Yaml, yaml::Yaml)>`
               found type `std::option::Option<(&yaml::Yaml, &yaml::Yaml)>`
    = help: here are some functions which might fulfill your needs:
            - .take()
            - .unwrap()
    = note: this error originates in a macro outside of the current crate

error: aborting due to 3 previous errors