Improve error span for async type inference error

src/librustc_typeck/check/generator_interior.rs

@@ -75,7 +75,7 @@ impl<'a, 'tcx> InteriorVisitor<'a, 'tcx> {
  // If unresolved type isn't a ty_var then unresolved_type_span is None
  self.fcx.need_type_info_err_in_generator(
  self.kind,
- unresolved_type_span.unwrap_or(yield_data.span),
+ unresolved_type_span.unwrap_or(source_span),
  unresolved_type,
  )
  .span_note(yield_data.span, &*note)

src/test/ui/async-await/async-error-span.rs

@@ -0,0 +1,17 @@
+// edition:2018
+#![feature(async_await)]
+
+// Regression test for issue #62382
+
+use std::future::Future;
+
+fn get_future() -> impl Future<Output = ()> {
+ panic!()
+}
+
+async fn foo() {
+ let a; //~ ERROR type inside `async` object must be known in this context
+ get_future().await;
+}
+
+fn main() {}

src/test/ui/async-await/async-error-span.stderr

@@ -0,0 +1,15 @@
+error[E0698]: type inside `async` object must be known in this context
+ --> $DIR/async-error-span.rs:13:9
+ |
+LL | let a;
+ | ^ cannot infer type
+ |
+note: the type is part of the `async` object because of this `await`
+ --> $DIR/async-error-span.rs:14:5
+ |
+LL | get_future().await;
+ | ^^^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0698`.