A private item was used outside its scope.
Erroneous code example:
```compile_fail,E0603
mod SomeModule {
const PRIVATE: u32 = 0x_a_bad_1dea_u32; // This const is private, so we
// can't use it outside of the
// `SomeModule` module.
}
println!("const value: {}", SomeModule::PRIVATE); // error: constant `PRIVATE`
// is private
```
In order to fix this error, you need to make the item public by using the `pub`
keyword. Example:
```
mod SomeModule {
pub const PRIVATE: u32 = 0x_a_bad_1dea_u32; // We set it public by using the
// `pub` keyword.
}
println!("const value: {}", SomeModule::PRIVATE); // ok!
```