error: unexpected `cfg` condition value: `jack`

[prasad83]

I was greeted with following:

error: unexpected `cfg` condition value: `jack`
  --> src/main.rs:54:9
   |
54 |         feature = "jack"
   |         ^^^^^^^^^^^^^^^^
   |
   = note: expected values for `feature` are: `default`
   = help: consider adding `jack` as a feature in `Cargo.toml`
   = note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg/cargo-specifics.html> for more information about checking conditional configuration
   = note: `-D unexpected-cfgs` implied by `-D warnings`
   = help: to override `-D warnings` add `#[allow(unexpected_cfgs)]

[prasad83]

Adding the following in Cargo.toml solved

[features]
default  = []
jack = [] # add this