fix #102946

2 files changed, 33 insertions, 0 deletions

diff --git a/src/test/ui/resolve/issue-102946.rs b/src/test/ui/resolve/issue-102946.rs
new file mode 100644
index 00000000000..c6feca6f32f
--- /dev/null
+++ b/src/test/ui/resolve/issue-102946.rs
@@ -0,0 +1,7 @@
+impl Error for str::Utf8Error {
+    //~^ ERROR cannot find trait `Error` in this scope
+    //~| ERROR ambiguous associated type
+    fn description(&self)  {}
+}
+
+fn main() {}
diff --git a/src/test/ui/resolve/issue-102946.stderr b/src/test/ui/resolve/issue-102946.stderr
new file mode 100644
index 00000000000..65be0258e6d
--- /dev/null
+++ b/src/test/ui/resolve/issue-102946.stderr
@@ -0,0 +1,26 @@
+error[E0405]: cannot find trait `Error` in this scope
+  --> $DIR/issue-102946.rs:1:6
+   |
+LL | impl Error for str::Utf8Error {
+   |      ^^^^^ not found in this scope
+   |
+help: consider importing this trait
+   |
+LL | use std::error::Error;
+   |
+
+error[E0223]: ambiguous associated type
+  --> $DIR/issue-102946.rs:1:16
+   |
+LL | impl Error for str::Utf8Error {
+   |                ^^^^^^^^^^^^^^
+   |
+help: you are looking for the module in `std`, not the primitive type
+   |
+LL | impl Error for std::str::Utf8Error {
+   |                +++++
+
+error: aborting due to 2 previous errors
+
+Some errors have detailed explanations: E0223, E0405.
+For more information about an error, try `rustc --explain E0223`.