Code compiles on playground but fails when passed via stdin to rustc

I almost think it would be a good thing to break autocfg occasionally and try to influence people away from using it. I run into crates that have issues working on nightly over, and over, and over because of bad auto-detection. I would really like a way to just say "I'm on at least the latest stable when you were published, use all those features" and bypass any attempt at detecting for MSRV's I don't care about or unstable features I do not want used.