# Static rustc_lint::builtin::UNEXPECTED_CFGS

source ·

    pub static UNEXPECTED_CFGS: &'static Lint

Expand description

The `unexpected_cfgs` lint detects unexpected conditional compilation conditions.

#### §Example

    rustc --check-cfg 'cfg()'

ⓘ

    #[cfg(widnows)]
    fn foo() {}

This will produce:

    warning: unexpected `cfg` condition name: `widnows`
     --> lint_example.rs:1:7
      |
    1 | #[cfg(widnows)]
      |       ^^^^^^^
      |
      = note: `#[warn(unexpected_cfgs)]` on by default

#### §Explanation

This lint is only active when `--check-cfg` arguments are being passed to the compiler and triggers whenever an unexpected condition name or value is used.

See the Checking Conditional Configurations section for more details.

See the Cargo Specifics section for configuring this lint in `Cargo.toml`.