1 error[E0658]: use of unstable library feature 'try_reserve': new API
2 --> $DIR/feature-gate-try_reserve.rs:3:7
4 LL | v.try_reserve(10);
7 = note: for more information, see https://github.com/rust-lang/rust/issues/48043
8 = help: add `#![feature(try_reserve)]` to the crate attributes to enable
10 error: aborting due to previous error
12 For more information about this error, try `rustc --explain E0658`.