error: character literal may only contain one codepoint
  --> $DIR/str-as-char.rs:4:14
   |
LL |     println!('●●');
   |              ^^^^
help: if you meant to write a `str` literal, use double quotes
   |
LL |     println!("●●");
   |              ^^^^

error: format argument must be a string literal
  --> $DIR/str-as-char.rs:4:14
   |
LL |     println!('●●');
   |              ^^^^
help: you might be missing a string literal to format with
   |
LL |     println!("{}", '●●');
   |              ^^^^^

error: aborting due to 2 previous errors