error: requires at least a format string argument
  --> $DIR/bad-format-args.rs:2:5
   |
LL |     format!();
   |     ^^^^^^^^^^
   |
   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)

error: expected token: `,`
  --> $DIR/bad-format-args.rs:3:16
   |
LL |     format!("" 1);
   |                ^ expected `,`

error: expected one of `,`, `.`, `?`, or an operator, found `1`
  --> $DIR/bad-format-args.rs:4:19
   |
LL |     format!("", 1 1);
   |                   ^ expected one of `,`, `.`, `?`, or an operator

error: aborting due to 3 previous errors