I just uninstalled Cursive and I see that my clj code highlighting went away (it was highlighted before uninstalling the plugin).
Also the REPL tool window button (lower right chrome) went away (it was there before—but, of course, the tool window didn't actually contain a running REPL)
I get a popup in lower-right of IntelliJ saying "Plugins supporting feature (Run Configuration[ClojuireScript]) is currentlyh not installed". When I hit the "Configure plugins…" link, a panel offering to install Cursive 1.7.0-2018.2 pops up. The description in that popup says:
Built on: 2018-09-20 14:26
Built from: 1.8.0-eap7
I hit "OK" to install the plugin and hit the link to Restart IntelliJ. After restart I see that syntax highlighting is happening on core.clj, and I have a REPL tool window (but no REPL). I can navigate to the definition of Clojure fns e.g. the testing macro in clojure.test or the println fn in clojure.core.
I created a brand new Leiningen project in IntelliJ. It's kind of interesting to me, that it creates a project dependent on Clojure 1.8.0—not 1.9.0 Hmm.Still no way to create a REPL. The "hello world" in this Leiningen project, when run, exits 0 but does not print anything to the IntelliJ console.
When creating a new IntelliJ project I see the "Clojure" type in the list, which says "3 JARs will be downloaded into lib directory; Project library Clojure-1.9.0 will be created". Creating a new project of that type, I'm able to make a core.clj that prints "hello world" to the console when run. But I have no way to create a REPL for it.