Auto-import of an item that's already conditionally-imported creates a duplicate import

[svix-jplatte]

• given an input like

  #[cfg(feature = "foo")]
  use std::collections::HashMap;
  
  fn bar() -> HashMap {
      todo!()
  }

• with foo being an inactive feature cfg in the current RA session
• when using the import assist on HashMap
• a second use std::collections::HashMap; is generated
• which will result in a duplicate import error when the code is compiled with --feature foo

rust-analyzer version: 0.4.2183-standalone
rustc version: 1.84.0-nightly (b8c8287 2024-11-03)
editor or extension: VSCode w/ RA v0.4.2183 (pre-release)

[flodiebold]

I wouldn't see this as a bug, it's just how cfgs work -- the code simply doesn't exist if the feature isn't enabled.
Better handling for this would be quite hard to implement since the import statement isn't analyzed at all if the feature isn't active.