Difficulty reading environment variables in Leiningen project.clj

env_var_lein_project.clj

; consider this example
(let [_ (prn (System/getenv))]

  (defproject your-clojure-app "1.0.0-SNAPSHOT"
    
    :mirrors {#".+" {:url "https://internal.artifactory.repo.com/repo"
                     :username :env/artifactory_username
                     :password :env/artifactory_password}}))

; in the above example I confirm that the environment variables that I want
; namely "artifactory_username" and "artifactory_password" are present, however
; they are NOT picked up using the Leiningen :env/artifactory_username :env/artifactory_password
; syntax

; consider this variant b/c maybe it's something simple like typecase sensitivity

(let [_ (prn (System/getenv))]

  (defproject your-clojure-app "1.0.0-SNAPSHOT"
    
    :mirrors {#".+" {:url "https://internal.artifactory.repo.com/repo"
                     :username :env/ARTIFACTORY_USERNAME
                     :password :env/ARTIFACTORY_PASSWORD}}))

; again the environment variables are present based on the 
; the stdout of (System/getenv) but yet the :env/ARTIFACTORY_USERNAME 
; and :env/ARTIFACTORY_PASSWORD yield nil


; in a last ditch effort to use environment variables
(let [_ (prn (System/getenv))
      artifactory_username (System/getenv "artifactory_username")
      artifactory_password (System/getenv "artifactory_password")]

  (defproject your-clojure-app "1.0.0-SNAPSHOT"
    
    :mirrors {#".+" {:url "https://internal.artifactory.repo.com/repo"
                     :username ~artifactory_username
                     :password ~artifactory_password}}))

; the above example works and I then successfully authenticate to my private mirror
; and pull down my dependencies

; what am I doing wrong with :env/ARTIFACTORY_USERNAME and :env/ARTIFACTORY_PASSWORD
; that they aren't yielding the correct result?

I just came across this answer. Will give it a try