MacOS compile failing

[davedbase]

I'm having trouble getting this to compile. I'm using a project called neon to build (which I suspect isn't causing the issue below).

I'm running the build on MacOS Mojave. I've added the edition 2018 to package in Cargo.toml and actix-web-async-await = "0.2.0" in the dependencies list. I have the latest Rust builds installed rustc 1.31.1 (b6c32da9b 2018-12-18).

The error I'm getting is:

neon info running cargo
   Compiling futures v0.1.25                                                                                                            
error[E0554]: #![feature] may not be used on the stable release channel                                                                 
   --> /Users/ddibiase-macbook/.cargo/registry/src/gitlite.zycloud.tk-1ecc6299db9ec823/futures-0.1.25/src/lib.rs:161:34                         
    |                                                                                                                                   
161 | #![cfg_attr(feature = "nightly", feature(pin))]                                                                                   
    |                                  ^^^^^^^^^^^^                                                                                     
                                                                                                                                        
error: aborting due to previous error                                                                                                   
                                                                                                                                        
For more information about this error, try `rustc --explain E0554`.                                                                     
error: Could not compile `futures`.                                                                                                     

To learn more, run the command again with --verbose.
neon ERR! cargo build failed