clojure/spec/alpha classpath issue

[eigenhombre]

(defproject x "0.1.0-SNAPSHOT"
  :description "FIXME: write description"
  :url "http://example.com/FIXME"
  :license {:name "Eclipse Public License"
            :url "http://www.eclipse.org/legal/epl-v10.html"}
  :dependencies [[org.clojure/clojure "1.8.0"]
                 [sparkfund/sails-forth "0.9.1"]])

(ns x.core
  (:require [sails-forth.client :as sf]))

gives

2. Unhandled clojure.lang.Compiler$CompilerException
   Error compiling sails_forth/client.clj at (1:1)

             Compiler.java: 7391  clojure.lang.Compiler/load
                   RT.java:  372  clojure.lang.RT/loadResourceScript
                   RT.java:  363  clojure.lang.RT/loadResourceScript
                   RT.java:  453  clojure.lang.RT/load
                   RT.java:  419  clojure.lang.RT/load
                  core.clj: 5893  clojure.core/load/fn
                  core.clj: 5892  clojure.core/load
                  core.clj: 5876  clojure.core/load
               RestFn.java:  408  clojure.lang.RestFn/invoke
                  core.clj: 5697  clojure.core/load-one
                  core.clj: 5692  clojure.core/load-one
                  core.clj: 5737  clojure.core/load-lib/fn
                  core.clj: 5736  clojure.core/load-lib
                  core.clj: 5717  clojure.core/load-lib
               RestFn.java:  142  clojure.lang.RestFn/applyTo
                  core.clj:  648  clojure.core/apply
                  core.clj: 5774  clojure.core/load-libs
                  core.clj: 5758  clojure.core/load-libs
               RestFn.java:  137  clojure.lang.RestFn/applyTo
                  core.clj:  648  clojure.core/apply
                  core.clj: 5796  clojure.core/require
                  core.clj: 5796  clojure.core/require
               RestFn.java:  408  clojure.lang.RestFn/invoke
                      REPL:    1  x.core/eval11743/loading--auto--
                      REPL:    1  x.core/eval11743
                      REPL:    1  x.core/eval11743
             Compiler.java: 6927  clojure.lang.Compiler/eval
             Compiler.java: 6916  clojure.lang.Compiler/eval
             Compiler.java: 6890  clojure.lang.Compiler/eval
                  core.clj: 3105  clojure.core/eval
                  core.clj: 3101  clojure.core/eval
                  main.clj:  240  clojure.main/repl/read-eval-print/fn
                  main.clj:  240  clojure.main/repl/read-eval-print
                  main.clj:  258  clojure.main/repl/fn
                  main.clj:  258  clojure.main/repl
                  main.clj:  174  clojure.main/repl
               RestFn.java:  137  clojure.lang.RestFn/applyTo
                  core.clj:  646  clojure.core/apply
                  core.clj:  641  clojure.core/apply
                regrow.clj:   18  refactor-nrepl.ns.slam.hound.regrow/wrap-clojure-repl/fn
               RestFn.java: 1523  clojure.lang.RestFn/invoke
    interruptible_eval.clj:   87  clojure.tools.nrepl.middleware.interruptible-eval/evaluate/fn
                  AFn.java:  152  clojure.lang.AFn/applyToHelper
                  AFn.java:  144  clojure.lang.AFn/applyTo
                  core.clj:  646  clojure.core/apply
                  core.clj: 1881  clojure.core/with-bindings*
                  core.clj: 1881  clojure.core/with-bindings*
               RestFn.java:  425  clojure.lang.RestFn/invoke
    interruptible_eval.clj:   85  clojure.tools.nrepl.middleware.interruptible-eval/evaluate
    interruptible_eval.clj:   55  clojure.tools.nrepl.middleware.interruptible-eval/evaluate
    interruptible_eval.clj:  222  clojure.tools.nrepl.middleware.interruptible-eval/interruptible-eval/fn/fn
    interruptible_eval.clj:  190  clojure.tools.nrepl.middleware.interruptible-eval/run-next/fn
                  AFn.java:   22  clojure.lang.AFn/run
   ThreadPoolExecutor.java: 1149  java.util.concurrent.ThreadPoolExecutor/runWorker
   ThreadPoolExecutor.java:  624  java.util.concurrent.ThreadPoolExecutor$Worker/run
               Thread.java:  748  java.lang.Thread/run

1. Caused by java.io.FileNotFoundException
   Could not locate clojure/spec/alpha__init.class or
   clojure/spec/alpha.clj on classpath.

It works with Clojure 1.9, but not Clojure 1.8.