error: expected one of: byte string literal, string literal, identifier
 --> $DIR/non-str.rs:4:22
  |
4 |     let _foo = cstr!(1);
  |                      ^

error: expected one of: byte string literal, string literal, identifier
 --> $DIR/non-str.rs:5:22
  |
5 |     let _foo = cstr!(("a"));
  |                      ^^^^^

error: expected one of: byte string literal, string literal, identifier
 --> $DIR/non-str.rs:6:22
  |
6 |     let _foo = cstr!(&1);
  |                      ^