error[E0308]: mismatched types
  --> $DIR/issue-20831-debruijn.rs:28:5
   |
LL | /     fn subscribe(&mut self, t : Box<dyn Subscriber<Input=<Self as Publisher>::Output> + 'a>) {
LL | |         // Not obvious, but there is an implicit lifetime here -------^
LL | |
LL | |
...  |
LL | |         self.sub = t;
LL | |     }
   | |_____^ lifetime mismatch
   |
   = note: expected type `'a`
              found type `'_`
note: the anonymous lifetime #2 defined on the method body at 28:5...
  --> $DIR/issue-20831-debruijn.rs:28:5
   |
LL | /     fn subscribe(&mut self, t : Box<dyn Subscriber<Input=<Self as Publisher>::Output> + 'a>) {
LL | |         // Not obvious, but there is an implicit lifetime here -------^
LL | |
LL | |
...  |
LL | |         self.sub = t;
LL | |     }
   | |_____^
note: ...does not necessarily outlive the lifetime `'a` as defined on the impl at 26:6
  --> $DIR/issue-20831-debruijn.rs:26:6
   |
LL | impl<'a> Publisher<'a> for MyStruct<'a> {
   |      ^^

error[E0308]: mismatched types
  --> $DIR/issue-20831-debruijn.rs:28:5
   |
LL | /     fn subscribe(&mut self, t : Box<dyn Subscriber<Input=<Self as Publisher>::Output> + 'a>) {
LL | |         // Not obvious, but there is an implicit lifetime here -------^
LL | |
LL | |
...  |
LL | |         self.sub = t;
LL | |     }
   | |_____^ lifetime mismatch
   |
   = note: expected type `'a`
              found type `'_`
note: the lifetime `'a` as defined on the impl at 26:6...
  --> $DIR/issue-20831-debruijn.rs:26:6
   |
LL | impl<'a> Publisher<'a> for MyStruct<'a> {
   |      ^^
note: ...does not necessarily outlive the anonymous lifetime #2 defined on the method body at 28:5
  --> $DIR/issue-20831-debruijn.rs:28:5
   |
LL | /     fn subscribe(&mut self, t : Box<dyn Subscriber<Input=<Self as Publisher>::Output> + 'a>) {
LL | |         // Not obvious, but there is an implicit lifetime here -------^
LL | |
LL | |
...  |
LL | |         self.sub = t;
LL | |     }
   | |_____^

error[E0495]: cannot infer an appropriate lifetime for lifetime parameter `'a` due to conflicting requirements
  --> $DIR/issue-20831-debruijn.rs:28:5
   |
LL | /     fn subscribe(&mut self, t : Box<dyn Subscriber<Input=<Self as Publisher>::Output> + 'a>) {
LL | |         // Not obvious, but there is an implicit lifetime here -------^
LL | |
LL | |
...  |
LL | |         self.sub = t;
LL | |     }
   | |_____^
   |
note: first, the lifetime cannot outlive the anonymous lifetime #2 defined on the method body at 28:5...
  --> $DIR/issue-20831-debruijn.rs:28:5
   |
LL | /     fn subscribe(&mut self, t : Box<dyn Subscriber<Input=<Self as Publisher>::Output> + 'a>) {
LL | |         // Not obvious, but there is an implicit lifetime here -------^
LL | |
LL | |
...  |
LL | |         self.sub = t;
LL | |     }
   | |_____^
note: ...but the lifetime must also be valid for the lifetime `'a` as defined on the impl at 26:6...
  --> $DIR/issue-20831-debruijn.rs:26:6
   |
LL | impl<'a> Publisher<'a> for MyStruct<'a> {
   |      ^^
note: ...so that the types are compatible
  --> $DIR/issue-20831-debruijn.rs:28:5
   |
LL | /     fn subscribe(&mut self, t : Box<dyn Subscriber<Input=<Self as Publisher>::Output> + 'a>) {
LL | |         // Not obvious, but there is an implicit lifetime here -------^
LL | |
LL | |
...  |
LL | |         self.sub = t;
LL | |     }
   | |_____^
   = note: expected  `Publisher<'_>`
              found  `Publisher<'_>`

error: aborting due to 3 previous errors

Some errors have detailed explanations: E0308, E0495.
For more information about an error, try `rustc --explain E0308`.