Rollup merge of #33320 - birkenfeld:issue31573, r=arielb1

diagnostics for E0432: imports are relative to crate root

This is curiously missing from both the short message and this long diagnostic.

Refs #31573 (not sure if it should be considered "fixed" as the short message still only refers to extern crates).

1 files changed, 7 insertions, 4 deletions

diff --git a/src/librustc_resolve/diagnostics.rs b/src/librustc_resolve/diagnostics.rs
index 0a8fce49ebb..56d3b927dc5 100644
--- a/src/librustc_resolve/diagnostics.rs
+++ b/src/librustc_resolve/diagnostics.rs
@@ -916,11 +916,14 @@ An import was unresolved. Erroneous code example:
 use something::Foo; // error: unresolved import `something::Foo`.
 ```
 
-Please verify you didn't misspell the import name or the import does exist
-in the module from where you tried to import it. Example:
+Paths in `use` statements are relative to the crate root. To import items
+relative to the current and parent modules, use the `self::` and `super::`
+prefixes, respectively. Also verify that you didn't misspell the import
+name and that the import exists in the module from where you tried to
+import it. Example:
 
 ```ignore
-use something::Foo; // ok!
+use self::something::Foo; // ok!
 
 mod something {
     pub struct Foo;
@@ -928,7 +931,7 @@ mod something {
 ```
 
 Or, if you tried to use a module from an external crate, you may have missed
-the `extern crate` declaration:
+the `extern crate` declaration (which is usually placed in the crate root):
 
 ```ignore
 extern crate homura; // Required to use the `homura` crate