tests/ui/cross/cross-crate-macro-backtrace/main.stderr

   1 error: 1 positional argument in format string, but no arguments were given
   2   --> $DIR/main.rs:6:5
   3    |
   4 LL |     myprintln!("{}");
   5    |     ^^^^^^^^^^^^^^^^
   6    |
   7    = note: this error originates in the macro `concat` which comes from the expansion of the macro `myprintln` (in Nightly builds, run with -Z macro-backtrace for more info)
   8
   9 error: aborting due to previous error
  10