error: no rules expected the token `a`
  --> $DIR/macro-non-lifetime.rs:6:8
   |
LL | macro_rules! m { ($x:lifetime) => { } }
   | -------------- when calling this macro
...
LL |     m!(a);
   |        ^ no rules expected this token in macro call
   |
note: while trying to match meta-variable `$x:lifetime`
  --> $DIR/macro-non-lifetime.rs:3:19
   |
LL | macro_rules! m { ($x:lifetime) => { } }
   |                   ^^^^^^^^^^^

error: aborting due to 1 previous error