I'm trying -- and failing -- to use environ 1.2.0 to create environment variables for codox inside project.clj.
I have in profiles.clj
{:dev {:env {:doc-dir "/home/me/some/dir"}}}
So far all good: .line-env is correctly created and I can pull the value in a repl.
However I cannot get the value inside project.clj
(defproject ....
  :codox {:output-path (environ.core/env :doc-dir) })
I get an error from lein codox:
Syntax error (IllegalArgumentException) compiling at (/tmp/form-init13693313479173922228.clj:1:74). 
No implementation of method: :as-file of protocol: #'clojure.java.io/Coercions found for class: clojure.lang.PersistentList 
codox works if I remove the call to environ.core.
What am I doing wrong?