error[E0621]: explicit lifetime required in the type of `lexer`
  --> $DIR/nondeterministic-lifetime-errors-15034.rs:19:9
   |
LL |         Parser { lexer: lexer }
   |         ^^^^^^^^^^^^^^^^^^^^^^^ lifetime `'a` required
   |
help: add explicit lifetime `'a` to the type of `lexer`
   |
LL |     pub fn new(lexer: &'a mut Lexer<'a>) -> Parser<'a> {
   |                                    ++++

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0621`.