Defining an alias with the different types should yield a warning.
This should say
However, if the annotations are = after parse-type, then it should not give a warning.
I would like to work on this issue if that is ok?
You can basically copy the approach of var warnings: https://github.com/clojure/core.typed/blob/master/module-check/src/main/clojure/clojure/core/typed/var_env.clj#L58-L64
This is the equivalent file for aliases: https://github.com/clojure/core.typed/blob/master/module-check/src/main/clojure/clojure/core/typed/name_env.clj
Added a patch
No longer possible single defalias is collected at runtime.