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