For example:
user=> (let [x 5] (m/match x ([] :seq) true :else false))
IllegalArgumentException Don't know how to create ISeq from: java.lang.Long clojure.lang.RT.seqFrom (RT.java:542)
The problem appears to be that empty seq patterns are converted to LiteralPatterns for (). IPatternCompile for LiteralPatterns checks if the literal is () -- if so it emits an {{empty?}} test without any check to see if the ocr is {{Seqable}}.