StackOverflowError

[devth]

I'm getting a StackOverflowError when running lein ring server, ending with Subprocess failed.

The stacktrace looks like this:

Exception in thread "main" java.lang.StackOverflowError
    at clojure.lang.APersistentSet.iterator(APersistentSet.java:155)
    at clojure.core.protocols$fn__5871.invoke(protocols.clj:73)
    at clojure.core.protocols$fn__5828$G__5823__5841.invoke(protocols.clj:13)
    at clojure.core$reduce.invoke(core.clj:6030)
    at ns_tracker.dependency$transitive.invoke(dependency.clj:15)
    at ns_tracker.dependency$transitive$fn__748.invoke(dependency.clj:14)
    at clojure.core.protocols$fn__5871.invoke(protocols.clj:76)
    at clojure.core.protocols$fn__5828$G__5823__5841.invoke(protocols.clj:13)
    at clojure.core$reduce.invoke(core.clj:6030)
    at ns_tracker.dependency$transitive.invoke(dependency.clj:15)
    at ns_tracker.dependency$transitive$fn__748.invoke(dependency.clj:14)
    at clojure.core.protocols$fn__5871.invoke(protocols.clj:76)
    at clojure.core.protocols$fn__5828$G__5823__5841.invoke(protocols.clj:13)
    at clojure.core$reduce.invoke(core.clj:6030)
    at ns_tracker.dependency$transitive.invoke(dependency.clj:15)
    at ns_tracker.dependency$transitive$fn__748.invoke(dependency.clj:14)

repeating...

I'm trying to add a web frontend to an existing app. lein run still works fine. Any ideas? I've been tweaking deps/versions in project.clj for hours to no avail.

[weavejester]

This project is pretty far out of date. I'll add a note to the README and deprecate the repository.

Try creating a project with lein new compojure <project name> instead.

[devth]

Thanks. Generated the new project, which ran fine, moved the config and "hello world" handler into my existing app and hit the same StackOverflowError.

I just used lein pedantic to resolve a bunch of transitive dependency issues, but that didn't help. My deps are:

[
   [org.clojure/clojure "1.4.0"],
   ; TODO - kill this some day. We're only relying on it for
   ; cond-let at this point.
   [org.clojure/clojure-contrib "1.2.0"]
   [org.clojars.adamwynne/http.async.client "0.4.1"
                                            :exclusions [com.ning/async-http-client]]
   [org.apache.commons/commons-lang3 "3.1"]
   [robert/hooke "1.3.0"]
   [clj-campfire "1.0.0"]
   [clj-time "0.4.4"]

   [org.clojure/data.json "0.1.2"]
   [org.clojure/tools.namespace "0.2.2"]
   [org.clojure/java.classpath "0.2.0"]
   [org.clojure/core.cache "0.6.2"]
   [org.clojure/tools.logging "0.2.3"]

   [clj-logging-config "1.9.7"]
   [log4j/log4j "1.2.16" :exclusions [javax.mail/mail
                                       javax.jms/jms
                                       com.sun.jdmk/jmxtools
                                       com.sun.jmx/jmxri]]
   [evaljs "0.1.2"]
   [clj-ssh "0.4.0" :exclusions [slingshot]]
   [useful "0.8.3-alpha8"]
   [clj-wordnik "0.1.0-alpha1"]
   [tentacles "0.2.2"]
   [clj-http "0.5.5"
             :exclusions [org.apache.httpcomponents/httpclient
                           org.apache.httpcomponents/httpcore
                           slingshot
                           commons-codec]]
   [org.clojure/data.xml "0.0.6"]
   [org.clojure/data.zip "0.1.1"]
   [clj-aws-s3 "0.3.2"]
   [overtone/at-at "1.0.0"]
   [com.draines/postal "1.9.0"]
   [twitter-api "0.6.12" :exclusions [org.apache.httpcomponents/httpcore]]
   [inflections "0.7.3"]
   [environ "0.3.0"]
   [com.bigml/closchema "0.1.8"]
   [org.clojure/java.jdbc "0.2.3"]
   [mysql/mysql-connector-java "5.1.6"]
   [cheshire "5.0.1"]

   ;;; [incanter "1.4.0"]
   [compojure "1.1.5"]
   ;;; [lib-noir "0.3.4" :exclusions [[org.clojure/tools.namespace]]]

]

And using :plugins [[lein-ring "0.8.0"]]

[devth]

Actually, new stacktrace is slightly different. The previous stacktrace was when using compojure 1.1.4.

Exception in thread "main" java.lang.StackOverflowError
    at clojure.lang.Util.equiv(Util.java:32)
    at clojure.lang.PersistentHashMap$BitmapIndexedNode.find(PersistentHashMap.java:615)
    at clojure.lang.PersistentHashMap$ArrayNode.find(PersistentHashMap.java:378)
    at clojure.lang.PersistentHashMap.valAt(PersistentHashMap.java:153)
    at clojure.lang.PersistentHashMap.valAt(PersistentHashMap.java:157)
    at clojure.lang.RT.get(RT.java:634)
...etc

[weavejester]

I think I'd need to see the full stack trace or the code that's generating the error in order to diagnose the problem.

[devth]

Edit: looks like stacktrace was too long for github comment. Moving to gist:

https://gist.github.com/4560755

project.clj:

  :ring {:handler yetibot.webapp.server/app}

src/yetibot/webapp/server.clj:

(ns yetibot.webapp.server
  (:use compojure.core)
  (:require [compojure.handler :as handler]
            [compojure.route :as route]))

(defroutes app-routes
  (GET "/" [] "Hello World")
  (route/not-found "Not Found"))

(def app
  (handler/site app-routes))

[weavejester]

It looks as if you might have a circular dependency in your source code. Could you check to see whether that's the case?

[devth]

I rm'd all code out src except my webapp dir and it runs. The thing I don't understand is - why does it matter what else I have in src? Does lein ring load all namespaces itself? That may be the problem if so, because I dynamically load namespaces already from my -main.

[weavejester]

The wrap-load middleware looks at the ns declarations at the top of each file and constructs a tree of dependencies. So if A requires B, and you modify B, it knows to reload B and then A.

That it's stack overflowing suggests you might have a circular dependency in your source files, e.g. A requires B requires C requires A again.

[devth]

It ended up being two problems:

1. a namespace was requiring itself
2. two namespaces were requiring core

Thanks for your help, @weavejester. Much appreciated.

[weavejester]

It might be an idea to add a better check for circular dependencies, even if they shouldn't be in the source to begin with.

[devth]

That would be very helpful. This was my first Clojure project, so remnants of having no idea what I was doing still lurk in my codebase. Also, Clojure's error messages are the worst!