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# Error code E0536

The `not` cfg-predicate was malformed.

Erroneous code example (using `cargo doc`):

    #![feature(doc_cfg)]
    #[doc(cfg(not()))]
    pub fn main() {

    }

The `not` predicate expects one cfg-pattern. Example:

    #![feature(doc_cfg)]
    #[doc(cfg(not(target_os = "linux")))] // ok!
    pub fn main() {

    }

For more information about the `cfg` macro, read the section on Conditional Compilation in the Reference.