error: The attribute `a` already use this function name.
 --> tests/compile_fail/same_function_used.rs:9:18
  |
9 |     #[function = "another_function"]
  |                  ^^^^^^^^^^^^^^^^^^

error: First use of `another_function` here.
 --> tests/compile_fail/same_function_used.rs:6:18
  |
6 |     #[function = "another_function"]
  |                  ^^^^^^^^^^^^^^^^^^