Clojurians Log v2

I created a new project with lein new duct, ran lein duct setup to generate initial configs, then attempted lein repl but I get the following inscrutable stacktrace:

Warning: implicit middleware found: lein-duct.plugin/middleware
Please declare all middleware in :middleware as implicit loading is deprecated.
[WARNING] No nREPL middleware descriptor in metadata of #'cemerick.piggieback/wrap-cljs-repl, see nrepl.middleware/set-descriptor!
Exception in thread "main" java.lang.AssertionError: Assert failed: transport-fn, compiling:(/private/var/folders/p1/75ymbpzj6x343_mbbnb4_nyh0000gn/T/form-init280034086082238156.clj:1:124)
	at clojure.lang.Compiler.load(Compiler.java:7526)
	at clojure.lang.Compiler.loadFile(Compiler.java:7452)
	at clojure.main$load_script.invokeStatic(main.clj:278)
	at clojure.main$init_opt.invokeStatic(main.clj:280)
	at clojure.main$init_opt.invoke(main.clj:280)
	at clojure.main$initialize.invokeStatic(main.clj:311)
	at clojure.main$null_opt.invokeStatic(main.clj:345)
	at clojure.main$null_opt.invoke(main.clj:342)
	at clojure.main$main.invokeStatic(main.clj:424)
	at clojure.main$main.doInvoke(main.clj:387)
	at clojure.lang.RestFn.applyTo(RestFn.java:137)
	at clojure.lang.Var.applyTo(Var.java:702)
	at clojure.main.main(main.java:37)
Caused by: java.lang.AssertionError: Assert failed: transport-fn
	at nrepl.core$connect.invokeStatic(core.clj:168)
	at nrepl.core$connect.doInvoke(core.clj:168)
	at clojure.lang.RestFn.invoke(RestFn.java:457)
	at nrepl.ack$send_ack.invokeStatic(ack.clj:45)
	at nrepl.ack$send_ack.invoke(ack.clj:41)
	at nrepl.server$start_server.invokeStatic(server.clj:146)
	at nrepl.server$start_server.doInvoke(server.clj:105)
	at clojure.lang.RestFn.invoke(RestFn.java:1096)
	at user$eval10946.invokeStatic(form-init280034086082238156.clj:1)
	at user$eval10946.invoke(form-init280034086082238156.clj:1)
	at clojure.lang.Compiler.eval(Compiler.java:7062)
	at clojure.lang.Compiler.eval(Compiler.java:7052)
	at clojure.lang.Compiler.eval(Compiler.java:7052)
	at clojure.lang.Compiler.load(Compiler.java:7514)
	... 12 more
REPL server launch timed out.

Any thoughts appreciated. 🙂