I was trying something in the rust playpen just now, and got frustrated that it wouldn’t let me use any unstable features. It seems to be on the beta channel, with no way to choose nightly. The version dropdown only has “master”. Can beta/nightly be offered as a choice here?
There is an open issue for it: https://github.com/rust-lang/rust-playpen/issues/83
In general, the playpen seems to need some love, any work there seems to be highly appreciated. The problem is that setting it up for testing is not the simplest thing to do because of the sandboxing (at least it was, last time I tried).
Thanks, I’ve subscribed to that issue, and if I get time I’ll see if I can figure it out…