error[E0599]: no function or associated item named `new` found for struct `GnomeButton` in the current scope
  --> tests/fail/tmpl_syntax_error.rs:35:28
   |
7  |   struct GnomeButton {}
   |   ------------------ function or associated item `new` not found for this struct
...
32 |   #[interpolate_traits(Button => GnomeButton)]
   |  ________________________________-
33 | | impl Factory<dyn TRAIT> for GnomeFactory {
34 | |     fn create(&self) -> Box<dyn TRAIT> {
35 | |         Box::new(CONCRETE::new())
   | |                           -^^^ function or associated item not found in `GnomeButton`
   | |___________________________|
   |

error[E0308]: mismatched types
  --> tests/fail/tmpl_syntax_error.rs:40:25
   |
40 |     fn create(&self) -> Box<TRAIT> {
   |        ------           ^^^^^^^^^^ expected `Box<Window>`, found `()`
   |        |
   |        implicitly returns `()` as its body has no tail or `return` expression
41 |         Box::new(CONCRETE::create());
   |                                     - help: remove this semicolon to return this value
   |
   = note: expected struct `Box<Window>`
           found unit type `()`