src/test/ui/issues/issue-41726.stderr

   1 error[E0596]: cannot borrow data in an index of `HashMap<String, Vec<String>>` as mutable
   2   --> $DIR/issue-41726.rs:5:9
   3    |
   4 LL |         things[src.as_str()].sort();
   5    |         ^^^^^^^^^^^^^^^^^^^^ cannot borrow as mutable
   6    |
   7    = help: trait `IndexMut` is required to modify indexed content, but it is not implemented for `HashMap<String, Vec<String>>`
   8
   9 error: aborting due to previous error
  10
  11 For more information about this error, try `rustc --explain E0596`.