- The `Spec` class maintains a special `_patches_in_order_of_appearance`
attribute on patch variants, but it is was preserved when specs are
copied.
- This caused issues for some builds
- Add special logic to `Spec` to preserve this variant on copy
- TODO: in the long term we should get rid of the special variant and
make it the responsibility of one of the variant classes.
13aca774e3