mod foo { pub fn bar() -> i32 { 1 } } fn bar() -> i32 { 2 } fn main() { let stderr = 3; eprintln!({stderr}); //~^ ERROR format argument must be a string literal //~| HELP quote your inlined format argument to use as string literal eprintln!({1}); //~^ ERROR format argument must be a string literal //~| HELP you might be missing a string literal to format with eprintln!({foo::bar()}); //~^ ERROR format argument must be a string literal //~| HELP you might be missing a string literal to format with eprintln!({bar()}); //~^ ERROR format argument must be a string literal //~| HELP you might be missing a string literal to format with eprintln!({1; 2}); //~^ ERROR format argument must be a string literal //~| HELP you might be missing a string literal to format with }