In CIDER the REPL buffer gets created on receiving a describe-session response from the nREPL session that will back the REPL buffer. There's a problem with determining the default ns for the REPL buffer as many people use nREPL servers started with lein (lein repl :headless) and expect the `:init-ns` option for their project to the honored, but there's no easy way for clients to know what the default namespace is. It'd be great if this information was returned by `describe-session`.
Perhaps clients should be able to create a session with a particular default namespace to avoid the need for code like https://github.com/technomancy/leiningen/blob/554861505c23763d6583fe3b1f236a08ad02a4ca/src/leiningen/repl.clj#L103. I noticed that current the default ns is hardcoded as `user`.