error: cannot find attribute `autodiff_reverse` in this scope
  --> $DIR/feature-gate-autodiff.rs:9:3
   |
LL | #[autodiff_reverse(dfoo)]
   |   ^^^^^^^^^^^^^^^^
   |
help: consider importing this attribute macro
   |
LL + use std::autodiff::autodiff_reverse;
   |

error: aborting due to 1 previous error