recursive rules with declare causes unbound fn exception

[miner]

I ran into a problem with recursive rules. I predeclared a var to get it to compile. However, at runtime, I get an unbound fn exception. Here's a simplified example. My work-around was to use a var in my recursive rule, rather than the normal function. Notice the xcon1 def. I couldn't find the problem in the squarepeg source. I hate to jump to any conclusions, but maybe it's a Clojure bug.

(ns miner.herbert.recursive
(:require [squarepeg.core :as sp]))

(declare mcon)

(def mint (sp/mkpr integer?))

(def mvec (sp/mksub (sp/mk1om mcon)))

(def mcon (sp/mkalt mint mvec))

_ (mcon '(42) {} {} {})

;=> {:i (), :b {}, :r 42, :s [42], :m {}}

_ (mcon '([42]) {} {} {})

; IllegalStateException Attempting to call unbound fn: #'miner.herbert.recursive/mcon
; clojure.lang.Var$Unbound.throwArity (Var.java:43)

;; Same thing with a slight variation of use the xcon1 var for the recursive rule.

(declare xcon)
;; work-around by using var
(def xcon1 #'xcon)

(def xint (sp/mkpr integer?))

(def xvec (sp/mksub (sp/mk1om xcon1)))

(def xcon (sp/mkalt xint xvec))

_ (xcon '(42) {} {} {})

;=> {:i (), :b {}, :r 42, :s [42], :m {}}

_ (xcon '([42]) {} {} {})

;=> {:i (), :b {}, :r [42], :s [42], :m {}}