error: generic return type '$T' cannot be bound — 'make' has no parameter mentioning '$T', so no call site can infer it
  --> examples/1165-diagnostics-generic-return-unbound.sx:10:15
   |
10 | make :: () -> $T { 0 }
   |               ^^

error: generic return type '$T' cannot be bound — 'Foo.weird' has no parameter mentioning '$T', so no call site can infer it
  --> examples/1165-diagnostics-generic-return-unbound.sx:14:30
   |
14 |     weird :: (self: *Foo) -> $T { 0 }
   |                              ^^

error: generic return type '$T' cannot be bound — 'IntBox.leak' has no parameter mentioning '$T', so no call site can infer it
  --> examples/1165-diagnostics-generic-return-unbound.sx:21:32
   |
21 |     leak :: (self: *IntBox) -> $T { 0 }
   |                                ^^