Reverting switching test to no_std and adjust output after rebase.

compiler/rustc_resolve/src/diagnostics.rs

@@ -1823,7 +1823,6 @@ crate fn show_candidates(
         let instead = if instead { " instead" } else { "" };
         let mut msg = format!("consider importing {} {}{}", determiner, kind, instead);
 
-        // Issue notes
         for note in accessible_path_strings.iter().map(|cand| cand.3.as_ref()).flatten() {
             err.note(note);
         }

src/test/ui/suggestions/suggest-tryinto-edition-change.rs

@@ -2,28 +2,30 @@
 // Edition 2021 change
 // edition:2018
 
-// We mark this no_std to avoid emitting suggestions for both `std` and `core` traits. These were
+fn test() {
-// inconsistently ordered between CI and at least one local build, causing test failures.
+    let _i: i16 = 0_i32.try_into().unwrap();
-#![no_std]
-#![crate_type = "lib"]
-
-pub fn test() {
-    let _i: Result<i16, _> = 0_i32.try_into();
     //~^ ERROR no method named `try_into` found for type `i32` in the current scope
     //~| NOTE method not found in `i32`
-    //~| NOTE 'core::convert::TryInto' is included in the prelude starting in Edition 2021
+    //~| NOTE 'std::convert::TryInto' is included in the prelude starting in Edition 2021
 
-    let _i: Result<i16, _> = TryFrom::try_from(0_i32);
+    let _i: i16 = TryFrom::try_from(0_i32).unwrap();
     //~^ ERROR failed to resolve: use of undeclared type
     //~| NOTE not found in this scope
+    //~| NOTE 'std::convert::TryFrom' is included in the prelude starting in Edition 2021
     //~| NOTE 'core::convert::TryFrom' is included in the prelude starting in Edition 2021
 
-    let _i: Result<i16, _> = TryInto::try_into(0_i32);
+    let _i: i16 = TryInto::try_into(0_i32).unwrap();
     //~^ ERROR failed to resolve: use of undeclared type
     //~| NOTE not found in this scope
+    //~| NOTE 'std::convert::TryInto' is included in the prelude starting in Edition 2021
     //~| NOTE 'core::convert::TryInto' is included in the prelude starting in Edition 2021
 
-    let _i: () = FromIterator::from_iter(core::iter::empty());
+    let _v: Vec<_> = FromIterator::from_iter(&[1]);
     //~^ ERROR failed to resolve: use of undeclared type
+    //~| NOTE 'std::iter::FromIterator' is included in the prelude starting in Edition 2021
     //~| NOTE 'core::iter::FromIterator' is included in the prelude starting in Edition 2021
 }
+
+fn main() {
+    test();
+}

src/test/ui/suggestions/suggest-tryinto-edition-change.stderr

@@ -1,53 +1,62 @@
 error[E0433]: failed to resolve: use of undeclared type `TryFrom`
-  --> $DIR/suggest-tryinto-edition-change.rs:16:30
+  --> $DIR/suggest-tryinto-edition-change.rs:11:19
    |
-LL |     let _i: Result<i16, _> = TryFrom::try_from(0_i32);
+LL |     let _i: i16 = TryFrom::try_from(0_i32).unwrap();
-   |                              ^^^^^^^ not found in this scope
+   |                   ^^^^^^^ not found in this scope
    |
+   = note: 'std::convert::TryFrom' is included in the prelude starting in Edition 2021
    = note: 'core::convert::TryFrom' is included in the prelude starting in Edition 2021
-help: consider importing this trait
+help: consider importing one of these items
    |
 LL | use core::convert::TryFrom;
    |
+LL | use std::convert::TryFrom;
+   |
 
 error[E0433]: failed to resolve: use of undeclared type `TryInto`
-  --> $DIR/suggest-tryinto-edition-change.rs:21:30
+  --> $DIR/suggest-tryinto-edition-change.rs:17:19
    |
-LL |     let _i: Result<i16, _> = TryInto::try_into(0_i32);
+LL |     let _i: i16 = TryInto::try_into(0_i32).unwrap();
-   |                              ^^^^^^^ not found in this scope
+   |                   ^^^^^^^ not found in this scope
    |
+   = note: 'std::convert::TryInto' is included in the prelude starting in Edition 2021
    = note: 'core::convert::TryInto' is included in the prelude starting in Edition 2021
-help: consider importing this trait
+help: consider importing one of these items
    |
 LL | use core::convert::TryInto;
    |
+LL | use std::convert::TryInto;
+   |
 
 error[E0433]: failed to resolve: use of undeclared type `FromIterator`
-  --> $DIR/suggest-tryinto-edition-change.rs:26:18
+  --> $DIR/suggest-tryinto-edition-change.rs:23:22
    |
-LL |     let _i: () = FromIterator::from_iter(core::iter::empty());
+LL |     let _v: Vec<_> = FromIterator::from_iter(&[1]);
-   |                  ^^^^^^^^^^^^
+   |                      ^^^^^^^^^^^^
    |
   ::: $SRC_DIR/core/src/iter/traits/collect.rs:LL:COL
    |
 LL | pub trait IntoIterator {
    | ---------------------- similarly named trait `IntoIterator` defined here
    |
+   = note: 'std::iter::FromIterator' is included in the prelude starting in Edition 2021
    = note: 'core::iter::FromIterator' is included in the prelude starting in Edition 2021
 help: a trait with a similar name exists
    |
-LL |     let _i: () = IntoIterator::from_iter(core::iter::empty());
+LL |     let _v: Vec<_> = IntoIterator::from_iter(&[1]);
-   |                  ~~~~~~~~~~~~
+   |                      ~~~~~~~~~~~~
-help: consider importing this trait
+help: consider importing one of these items
    |
 LL | use core::iter::FromIterator;
    |
+LL | use std::iter::FromIterator;
+   |
 
 error[E0599]: no method named `try_into` found for type `i32` in the current scope
-  --> $DIR/suggest-tryinto-edition-change.rs:11:36
+  --> $DIR/suggest-tryinto-edition-change.rs:6:25
    |
-LL |     let _i: Result<i16, _> = 0_i32.try_into();
+LL |     let _i: i16 = 0_i32.try_into().unwrap();
-   |                                    ^^^^^^^^ method not found in `i32`
+   |                         ^^^^^^^^ method not found in `i32`
    |
   ::: $SRC_DIR/core/src/convert/mod.rs:LL:COL
    |
@@ -55,10 +64,10 @@ LL |     fn try_into(self) -> Result<T, Self::Error>;
    |        -------- the method is available for `i32` here
    |
    = help: items from traits can only be used if the trait is in scope
-   = note: 'core::convert::TryInto' is included in the prelude starting in Edition 2021
+   = note: 'std::convert::TryInto' is included in the prelude starting in Edition 2021
 help: the following trait is implemented but not in scope; perhaps add a `use` for it:
    |
-LL | use core::convert::TryInto;
+LL | use std::convert::TryInto;
    |
 
 error: aborting due to 4 previous errors