| #### Note: this error code is no longer emitted by the compiler. | |
| The `feature` attribute was badly formed. | |
| Erroneous code example: | |
| ```compile_fail | |
| #![feature(foo_bar_baz, foo(bar), foo = "baz", foo)] // error! | |
| #![feature] // error! | |
| #![feature = "foo"] // error! | |
| ``` | |
| The `feature` attribute only accept a "feature flag" and can only be used on | |
| nightly. Example: | |
| ```ignore (only works in nightly) | |
| #![feature(flag)] | |
| ``` |