Return type hinting, imports, and namespace boundaries

core.clj

(ns clj.core
  "Relying namespace."
  (:require [clj.util :as u]))

(defn config-dir
  "Call "
  [conf]
  (.getCanonicalFile (u/make-file)))

util.clj

(ns clj.util
  "Common utilities."
  (:import java.io.File))

(defn make-file
  "Type-hinted to return a File."
  ^File []
  (File. "/etc"))

zzz stack trace.txt

timmc@thunk:~/tmp/clj$ lein test
Exception in thread "main" java.lang.IllegalArgumentException: Unable to resolve classname: File, compiling:(clj/core.clj:8)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6416)
	at clojure.lang.Compiler.analyze(Compiler.java:6216)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6397)
	at clojure.lang.Compiler.analyze(Compiler.java:6216)
	at clojure.lang.Compiler.analyze(Compiler.java:6177)
	at clojure.lang.Compiler$BodyExpr$Parser.parse(Compiler.java:5572)
	at clojure.lang.Compiler$FnMethod.parse(Compiler.java:5008)
	at clojure.lang.Compiler$FnExpr.parse(Compiler.java:3629)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6407)
	at clojure.lang.Compiler.analyze(Compiler.java:6216)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6397)
	at clojure.lang.Compiler.analyze(Compiler.java:6216)
	at clojure.lang.Compiler.access$100(Compiler.java:37)
	at clojure.lang.Compiler$DefExpr$Parser.parse(Compiler.java:492)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6409)
	at clojure.lang.Compiler.analyze(Compiler.java:6216)
	at clojure.lang.Compiler.analyze(Compiler.java:6177)
	at clojure.lang.Compiler.eval(Compiler.java:6469)
	at clojure.lang.Compiler.load(Compiler.java:6902)
	at clojure.lang.RT.loadResourceScript(RT.java:357)
	at clojure.lang.RT.loadResourceScript(RT.java:348)
	at clojure.lang.RT.load(RT.java:427)
	at clojure.lang.RT.load(RT.java:398)
	at clojure.core$load$fn__4610.invoke(core.clj:5386)
	at clojure.core$load.doInvoke(core.clj:5385)
	at clojure.lang.RestFn.invoke(RestFn.java:408)
	at clojure.core$load_one.invoke(core.clj:5200)
	at clojure.core$load_lib.doInvoke(core.clj:5237)
	at clojure.lang.RestFn.applyTo(RestFn.java:142)
	at clojure.core$apply.invoke(core.clj:602)
	at clojure.core$load_libs.doInvoke(core.clj:5271)
	at clojure.lang.RestFn.applyTo(RestFn.java:137)
	at clojure.core$apply.invoke(core.clj:604)
	at clojure.core$use.doInvoke(core.clj:5363)
	at clojure.lang.RestFn.invoke(RestFn.java:408)
	at clj.test.core$eval72$loading__4505__auto____73.invoke(core.clj:1)
	at clj.test.core$eval72.invoke(core.clj:1)
	at clojure.lang.Compiler.eval(Compiler.java:6465)
	at clojure.lang.Compiler.eval(Compiler.java:6455)
	at clojure.lang.Compiler.load(Compiler.java:6902)
	at clojure.lang.RT.loadResourceScript(RT.java:357)
	at clojure.lang.RT.loadResourceScript(RT.java:348)
	at clojure.lang.RT.load(RT.java:427)
	at clojure.lang.RT.load(RT.java:398)
	at clojure.core$load$fn__4610.invoke(core.clj:5386)
	at clojure.core$load.doInvoke(core.clj:5385)
	at clojure.lang.RestFn.invoke(RestFn.java:408)
	at clojure.core$load_one.invoke(core.clj:5200)
	at clojure.core$load_lib.doInvoke(core.clj:5237)
	at clojure.lang.RestFn.applyTo(RestFn.java:142)
	at clojure.core$apply.invoke(core.clj:602)
	at clojure.core$load_libs.doInvoke(core.clj:5271)
	at clojure.lang.RestFn.applyTo(RestFn.java:137)
	at clojure.core$apply.invoke(core.clj:602)
	at clojure.core$require.doInvoke(core.clj:5352)
	at clojure.lang.RestFn.invoke(RestFn.java:421)
	at user$eval40.invoke(NO_SOURCE_FILE:1)
	at clojure.lang.Compiler.eval(Compiler.java:6465)
	at clojure.lang.Compiler.eval(Compiler.java:6455)
	at clojure.lang.Compiler.eval(Compiler.java:6431)
	at clojure.core$eval.invoke(core.clj:2795)
	at clojure.main$eval_opt.invoke(main.clj:296)
	at clojure.main$initialize.invoke(main.clj:315)
	at clojure.main$null_opt.invoke(main.clj:348)
	at clojure.main$main.doInvoke(main.clj:426)
	at clojure.lang.RestFn.invoke(RestFn.java:421)
	at clojure.lang.Var.invoke(Var.java:405)
	at clojure.lang.AFn.applyToHelper(AFn.java:163)
	at clojure.lang.Var.applyTo(Var.java:518)
	at clojure.main.main(main.java:37)
Caused by: java.lang.IllegalArgumentException: Unable to resolve classname: File
	at clojure.lang.Compiler$HostExpr.tagToClass(Compiler.java:1003)
	at clojure.lang.Compiler$InvokeExpr.getJavaClass(Compiler.java:3446)
	at clojure.lang.Compiler$HostExpr$Parser.parse(Compiler.java:885)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6409)

OK, this only seems to happen with arglist hinting, not fn name hinting.