最小可行性实例
clojure.core.async=> (fn [] (go
(let [a nil
foo (identity a)]
(<!/!!!)),
CompilerException java.lang.RuntimeException: Unable to resolve symbol: a in this context, compiling:(NO_SOURCE_PATH:1207:41)
*补丁*: 0001-ASYNC-212-fix-expressions-with-nil-local.patch