How to suppress output to stderr in a clojure program - clojure

Question

I want to produce a command line version of a clojure library using clojure/tools.cli and lein bin. This works fine except I am getting output to stderr when I run the script. This particular library has functions that override some basic functions, so naturally there are warnings when the clojure code is compiled. I know this is generally a bad idea but after careful consideration in this case I believe it is the best way to go. How do I stop these messages from appearing every time I run the script?
I added slf4j-nop to the dependencies as recommended in the monger documentation to suppress unwanted messages from monger, and this works, but has no effect on the warnings from the clojure compiler.
I have also tried using slf4j-log as detailed here: suppress output from `clojure.tools.logging` but without success.
Here is some of the code:
project.clj
(defproject image-search "0.1.0-SNAPSHOT"
:description "Search for images containing specific metadata"
:url "http://github.com/soulflyer/image-search"
:license {:name "Eclipse Public License"
:url "http://www.eclipse.org/legal/epl-v10.html"}
:dependencies [[org.clojure/clojure "1.7.0"]
[org.clojure/tools.cli "0.3.3"]
[org.slf4j/slf4j-nop "1.7.21"]
[image-lib "0.1.1-SNAPSHOT"]]
:main image-search.command-line
:bin {:name "image-search"
:bin-path "~/bin"})
and command_line.clj:
(ns image-search.command-line
(:require [image-search.core :refer [open all-images ifeq ifin ]]
[clojure.tools.cli :refer :all])
(:gen-class))
(def cli-options
[["-c" "--count" "Counts the results"]
["-D" "--database DATABASE" "specifies database to use"
:default "photos"]
["-I" "--image-collection IMAGE-COLLECTION" "specifies the image collection"
:default "images"]
["-K" "--keyword-collection KEYWORD-COLLECTION" "specifies the keyword collection"
:default "keywords"]
["-h" "--help"]
["-i" "--iso ISO" "Search on ISO value"]
["-s" "--shutter SHUTTER-SPEED" "search on SHUTTER-SPEED"]
["-f" "--aperture APERTURE" "search on APERTURE"]
["-y" "--year YEAR" "search on YEAR"]
["-m" "--month MONTH" "search on MONTH"]
["-M" "--model MODEL" "search by camera model"]
["-p" "--project PROJECT" "search photos in PROJECT"]
["-k" "--keyword KEYWORD" "search for KEYWORD"]])
(defn print-count [pics]
(println (count pics)))
(defn -main
"I don't do a whole lot ... yet."
[& args]
(let [{:keys [options arguments errors summary]} (parse-opts args cli-options)
output-function (if (:count options) print-count open)]
(-> all-images
(ifeq :ISO-Speed-Ratings (:iso options))
(ifeq :Year (:year options))
(ifeq :Month (:month options))
(ifin :Project (:project options))
(ifeq :F-Number (:aperture options))
(ifin :Keywords (:keyword options))
(ifin :Model (:model options))
(output-function))))
I run lein bin, then run the executable it produces and get something like this:
(master) image-search: image-search -i 640 -c
WARNING: or already refers to: #'clojure.core/or in namespace: image-search.core, being replaced by: #'image-search.core/or
WARNING: and already refers to: #'clojure.core/and in namespace: image-search.core, being replaced by: #'image-search.core/and
Note that the 2 warning are referring to functions I don't use in the command line version. I am not even including them. They are not in the list given to refer when I :require the library. They are, however, important to the library when I'm using it from the repl or cider. So I really don't want to rename them.

Answer 1

You can remove the warning by adding following to your (ns image-search.core) declaration:
(ns image-search.core
(:refer-clojure :exclude [or and])
With that change you can still use the original Clojure's or and and by fully qualifying them:
`clojure.core/or`
`clojure.core/and`
Without that change the compiler warns you that you are overriding your namespace binding of or and and as they are by default bound to functions from clojure.core/or and clojure/and vars.