documented/fixed error-codes/E0152-duplicate-lang-items.rs

Author: spencer3035

tests/ui/duplicate_entry_error.stderr

@@ -1,8 +1,10 @@
-//@ normalize-stderr: "loaded from .*libstd-.*.rlib" -> "loaded from SYSROOT/libstd-*.rlib"
-// note-pattern: first defined in crate `std`.
-
-// Test for issue #31788 and E0152
+//! Validates the correct printing of E0152 in the case of duplicate "lang_item" function
+//! definitions.
+//!
+//! Error: E0152
+//! Issue: <https://github.com/rust-lang/rust/issues/31788>
 
+//@ error-pattern: first defined in crate `std`
 #![feature(lang_items)]
 
 extern crate core;
@@ -11,7 +13,7 @@ use core::panic::PanicInfo;
 
 #[lang = "panic_impl"]
 fn panic_impl(info: &PanicInfo) -> ! {
-//~^ ERROR: found duplicate lang item `panic_impl`
+    //~^ ERROR: found duplicate lang item `panic_impl`
     loop {}
 }
 

tests/ui/error-codes/E0152-duplicate-lang-items.rs

@@ -0,0 +1,16 @@
+error[E0152]: found duplicate lang item `panic_impl`
+  --> $DIR/E0152-duplicate-lang-items.rs:14:1
+   |
+LL | / fn panic_impl(info: &PanicInfo) -> ! {
+LL | |
+LL | |     loop {}
+LL | | }
+   | |_^
+   |
+   = note: the lang item is first defined in crate `std` (which `E0152_duplicate_lang_items` depends on)
+   = note: first definition in `std` loaded from $BUILD_DIR/x86_64-unknown-linux-gnu/stage1/lib/rustlib/x86_64-unknown-linux-gnu/lib/libstd-df4a2d41d5905242.rlib
+   = note: second definition in the local crate (`E0152_duplicate_lang_items`)
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0152`.