Error code E0452

An invalid lint attribute has been given.

Erroneous code example:

#![allow(unused)]
#![allow(foo = "")] // error: malformed lint attribute
fn main() {
}

Lint attributes only accept a list of identifiers (where each identifier is a lint name). Ensure the attribute is of this form:

#![allow(unused)]
#![allow(foo)] // ok!
fn main() {
// or:
#![allow(foo, foo2)] // ok!
}