error: expected identifier, found keyword `true`
  --> $DIR/issue-44406.rs:18:10
   |
18 |     foo!(true);
   |          ^^^^

error: expected type, found keyword `true`
  --> $DIR/issue-44406.rs:18:10
   |
13 |         bar(baz: $rest)
   |                - help: did you mean to use `;` here?
...
18 |     foo!(true);
   |          ^^^^ expecting a type here because of type ascription

error: expected one of `!`, `&&`, `&`, `(`, `*`, `.`, `;`, `<`, `?`, `[`, `_`, `extern`, `fn`, `for`, `impl`, `unsafe`, `}`, an operator, or lifetime, found `true`
  --> $DIR/issue-44406.rs:18:10
   |
13 |         bar(baz: $rest)
   |                 - expected one of 19 possible tokens here
...
18 |     foo!(true);
   |          ^^^^ unexpected token

error: aborting due to 3 previous errors