The piece of code is as follows:
// Log in to Discord using a bot token from the environment                  
let discord = Discord::from_bot_token(                                       
    &env::var("DISCORD_TOKEN").unwrap()                                      
).expect("login failed");
I get an error saying it is unable to find the environment variable DISCORD_TOKEN. 
My environment does show the variable:
myawesomename$env | grep DISCORD
DISCORD_TOKEN=you'llneverknow
If I print all the keys and values that Rust knows:
for (key, value) in env::vars() {                                            
    println!("{}: {}", key, value);                                      
}
It doesn't show the environment variable.
On a similar note, when I do env | grep CARGO, none of the CARGO variables exist, but they are printed in the Rust code.
There is something I fundamentally doesn't understand about the profile/system env variables Rust is looking at (which, I assumed, are the variables in the environment in which the process is launched).
UPDATE: I don't know what I change, but it works now. I apologize for intruding on everyone's time. Thank you for helping me look into this though.
 
    