warning: could not parse code block as Rust code
  --> $DIR/ignore-block-help.rs:3:5
   |
LL |   /// ```ignore (to-prevent-tidy-error)
   |  _____^
LL | | /// let heart = '❤️';
LL | | /// ```
   | |_______^
   |
help: `ignore` code blocks require valid Rust code for syntax highlighting; mark blocks that do not contain Rust code as text: ```text
  --> $DIR/ignore-block-help.rs:3:5
   |
LL | /// ```ignore (to-prevent-tidy-error)
   |     ^^^
   = note: error from rustc: character literal may only contain one codepoint
   = note: `#[warn(rustdoc::invalid_rust_codeblocks)]` on by default

warning: 1 warning emitted