Instrument the code.

src/parser/util.rs

@@ -108,6 +108,7 @@ pub fn non_whitespace_character(input: &str) -> Res<&str, char> {
 }
 
 /// Check that we are at the start of a line
+#[tracing::instrument(ret, level = "debug")]
 pub fn exit_matcher_parser<'r, 's>(
     context: Context<'r, 's>,
     input: &'s str,