error[E0252]: the name `Arc` is defined multiple times
  --> $DIR/issue-26886.rs:2:5
   |
LL | use std::sync::{self, Arc};
   |                       --- previous import of the type `Arc` here
LL | use std::sync::Arc; //~ ERROR the name `Arc` is defined multiple times
   | ----^^^^^^^^^^^^^^-
   | |   |
   | |   `Arc` reimported here
   | help: remove unnecessary import
   |
   = note: `Arc` must be defined only once in the type namespace of this module

error[E0252]: the name `sync` is defined multiple times
  --> $DIR/issue-26886.rs:4:5
   |
LL | use std::sync::{self, Arc};
   |                 ---- previous import of the module `sync` here
...
LL | use std::sync; //~ ERROR the name `sync` is defined multiple times
   | ----^^^^^^^^^-
   | |   |
   | |   `sync` reimported here
   | help: remove unnecessary import
   |
   = note: `sync` must be defined only once in the type namespace of this module

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0252`.