D7503: rust-dirs: address failing tests for `dirs` impl with a temporary fix

[yuja (Yuya Nishihara)]

yuja added a comment.


  Many unhandled results:
  
    warning: unused `std::result::Result` that must be used
      --> hg-core/src/dirstate/dirs_multiset.rs:42:21
       |
    42 |                     multiset.add_path(filename);
       |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
       |
       = note: #[warn(unused_must_use)] on by default
       = note: this `Result` may be an `Err` variant, which should be handled
    
    warning: unused `std::result::Result` that must be used
      --> hg-core/src/dirstate/dirs_multiset.rs:45:17
       |
    45 |                 multiset.add_path(filename);
       |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
       |
       = note: this `Result` may be an `Err` variant, which should be handled
    
    warning: unused `std::result::Result` that must be used
      --> hg-core/src/dirstate/dirs_multiset.rs:59:13
       |
    59 |             multiset.add_path(filename);
       |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
       |
       = note: this `Result` may be an `Err` variant, which should be handled
    
    warning: unused `std::result::Result` that must be used
       --> hg-core/src/dirstate/dirstate_map.rs:129:17
        |
    129 |                 all_dirs.add_path(filename);
        |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        |
        = note: this `Result` may be an `Err` variant, which should be handled
  
  Might be better to do `path.check_state()` in cpython layer, and insert
  `debug_assert` to hg-core.

REPOSITORY
  rHG Mercurial

CHANGES SINCE LAST ACTION
  https://phab.mercurial-scm.org/D7503/new/

REVISION DETAIL
  https://phab.mercurial-scm.org/D7503

To: Alphare, #hg-reviewers
Cc: yuja, marmoute, durin42, kevincox, mercurial-devel