1 error[E0658]: specialization is unstable
2 --> $DIR/track6.rs:11:5
4 LL | default fn bar() {}
6 -Ztrack-diagnostics: created at $COMPILER_DIR/rustc_session/src/parse.rs:93:5
8 = note: see issue #31844 <https://github.com/rust-lang/rust/issues/31844> for more information
9 = help: add `#![feature(specialization)]` to the crate attributes to enable
11 error: aborting due to previous error
13 For more information about this error, try `rustc --explain E0658`.