error[E0403]: the name `T1` is already used for a generic parameter in this item's generic parameters
  --> $DIR/gat-trait-path-generic-type-arg.rs:10:12
   |
LL | impl <T, T1> Foo for T {
   |          -- first use of `T1`
LL |     type F<T1> = &[u8];
   |            ^^ already used

error[E0106]: missing lifetime specifier
  --> $DIR/gat-trait-path-generic-type-arg.rs:10:18
   |
LL |     type F<T1> = &[u8];
   |                  ^ expected named lifetime parameter
   |
help: consider introducing a named lifetime parameter
   |
LL |     type F<'a, T1> = &'a [u8];
   |            +++        ++

error: aborting due to 2 previous errors

Some errors have detailed explanations: E0106, E0403.
For more information about an error, try `rustc --explain E0106`.