Rust errors / Everything else
Rust compiler error · checked with rustc 1.99.0
Rust error E0264: unknown external lang item: `copy`
What it meansAn unknown external lang item was used.
What rustc prints
error[E0264]: unknown external lang item: `copy`
--> main.rs:5:5
|
5 | #[lang = "copy"] // error: unknown external lang item: `copy`
| ^^^^^^^^^^^^^^^^Real output of rustc 1.99.0 compiling the official example below (2021 edition). Your names and line numbers will differ; the first line is the part to match.
E0264Everything else
Activein rustc 1.99.0
8related errors linked below
The compiler team's explanation
An unknown external lang item was used.
Erroneous code example:
#![feature(lang_items)]
#![allow(internal_features)]
extern "C" {
#[lang = "copy"] // error: unknown external lang item: `copy`
fn copy();
}A list of available external lang items is available in compiler/rustc_hir/src/weak_lang_items.rs. Example:
#![feature(lang_items)]
#![allow(internal_features)]
extern "C" {
#[lang = "panic_impl"] // ok!
fn cake();
}From rustc --explain E0264 (1.99.0), part of the Rust project, MIT or Apache-2.0. Official page.
Related errors
- E0061this function takes N arguments but M were supplied
- E0412cannot find type in this scope
- E0515cannot return reference to local variable
- E0728await is only allowed inside async functions and blocks
- E0133call to unsafe function `f` is unsafe and requires unsafe function or block
- E0152found duplicate lang item `owned_box`
- E0267`break` inside of a closure
- E0268`break` outside of a loop or labeled block
Up next
Often hit nextE0061: this function takes N arguments but M were suppliedA related error from the same family.Read it next →Did this answer your question?