Clojure fails to parse "nil" as a map namespace

Question

Typing {:nil/a 1} in the Clojure 1.10.1 REPL prints #:nil{:a 1}.

But typing #:nil{:a 1} gives me this error:

             java.lang.RuntimeException: Namespaced map must specify a valid namespace: null
clojure.lang.LispReader$ReaderException: java.lang.RuntimeException: Namespaced map must specify a valid namespace: null
             clojure.lang.ExceptionInfo: 
             java.lang.RuntimeException: Unmatched delimiter: }
clojure.lang.LispReader$ReaderException: java.lang.RuntimeException: Unmatched delimiter: }
             clojure.lang.ExceptionInfo:

(clojure.edn/read-string (pr-str {:nil/a 1})) fails with the following exception:

java.lang.RuntimeException: Namespaced map must specify a valid namespace: null

This works with other namespaces, too:

(clojure.edn/read-string (pr-str {:1/a 1}))
; => java.lang.RuntimeException: Namespaced map must specify a valid namespace: 1
(clojure.edn/read-string (pr-str {:true/a 1}))
; => java.lang.RuntimeException: Namespaced map must specify a valid namespace: true

This doesn’t really make sense because (clojure.edn/read-string ":true/a") works perfectly fine.

Answer 1

Seems like a bug, filed at https://clojure.atlassian.net/browse/CLJ-2567