error: requires at least a format string argument
  --> $DIR/ifmt-bad-format-args.rs:2:5
   |
LL |     format_args!(); //~ ERROR: requires at least a format string argument
   |     ^^^^^^^^^^^^^^^

error: format argument must be a string literal
  --> $DIR/ifmt-bad-format-args.rs:3:18
   |
LL |     format_args!(|| {}); //~ ERROR: must be a string literal
   |                  ^^^^^
help: you might be missing a string literal to format with
   |
LL |     format_args!("{}", || {}); //~ ERROR: must be a string literal
   |                  ^^^^^

error: aborting due to 2 previous errors