1. on-the-fly diagnostics are mostly unimplemented (`cargo check` diagnostics will be shown when saving a file)
2. some settings are required for procedural macro and build script support (`rust-analyzer.cargo.loadOutDirsFromCheck`, `rust-analyzer.procMacro.enable`): #6448
3. some platform-specific imports are not resolved: #6038
Otherwise please try to provide information which will help us to fix the issue faster. Minimal reproducible examples with few dependencies are especially lovely <3.