error[E0658]: gen blocks are experimental
  --> $DIR/feature-gate-gen_blocks.rs:5:5
   |
LL |     gen {};
   |     ^^^^^
   |
   = note: see issue #117078 <https://github.com/rust-lang/rust/issues/117078> for more information
   = help: add `#![feature(gen_blocks)]` to the crate attributes to enable

error[E0658]: gen blocks are experimental
  --> $DIR/feature-gate-gen_blocks.rs:13:5
   |
LL |     gen {};
   |     ^^^^^
   |
   = note: see issue #117078 <https://github.com/rust-lang/rust/issues/117078> for more information
   = help: add `#![feature(gen_blocks)]` to the crate attributes to enable

error[E0282]: type annotations needed
  --> $DIR/feature-gate-gen_blocks.rs:5:9
   |
LL |     gen {};
   |         ^^ cannot infer type

error: aborting due to 3 previous errors

Some errors have detailed explanations: E0282, E0658.
For more information about an error, try `rustc --explain E0282`.