Rust errors / Attributes, macros and features
Rust compiler error · checked with rustc 1.99.0
Rust error E0538: malformed `deprecated` attribute input
What it meansAttribute contains same meta item more than once.
What rustc prints
error[E0538]: malformed `deprecated` attribute input
--> main.rs:1:3
|
1 | #[deprecated(
| ___^
2 | | since="1.0.0",
3 | | note="First deprecation note.",
4 | | note="Second deprecation note." // error: multiple same meta item
| | ------------------------------- found `note` used as a key more than once
5 | | )]
| |_^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.
E0538Attributes, macros and features
Activein rustc 1.99.0
5related errors linked below
The compiler team's explanation
Attribute contains same meta item more than once.
Erroneous code example:
#[deprecated(
since="1.0.0",
note="First deprecation note.",
note="Second deprecation note." // error: multiple same meta item
)]
fn deprecated_function() {}Meta items are the key-value pairs inside of an attribute. Each key may only be used once in each attribute.
To fix the problem, remove all but one of the meta items with the same key.
Example:
#[deprecated(
since="1.0.0",
note="First deprecation note."
)]
fn deprecated_function() {}From rustc --explain E0538 (1.99.0), part of the Rust project, MIT or Apache-2.0. Official page.
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