error[E0263]: lifetime name `'a` declared twice in the same scope
  --> $DIR/duplicate_lifetimes.rs:8:14
   |
LL |     fn g<$a, 'a>() {}
   |              ^^ declared twice
...
LL | m!('a);
   | ------
   | |  |
   | |  previous declaration here
   | in this macro invocation
   |
   = note: this error originates in the macro `m` (in Nightly builds, run with -Z macro-backtrace for more info)

error[E0263]: lifetime name `'a` declared twice in the same scope
  --> $DIR/duplicate_lifetimes.rs:13:14
   |
LL |     fn h<$a, 'a>() {}
   |              ^^ declared twice
...
LL | n!('a);
   | ------
   | |  |
   | |  previous declaration here
   | in this macro invocation
   |
   = note: this error originates in the macro `n` (in Nightly builds, run with -Z macro-backtrace for more info)

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0263`.