Troubleshooting

This section of the manual tries to summarize the most common problems that you may encounter while using nREPL and their solutions.

Generally it’s also a good idea to check whether the problem you’ve experienced is not a bug that’s already reported on our issue tracker.

Middleware

Warnings when Starting nREPL

If you encounter something like:

[WARNING] No nREPL middleware descriptor in metadata of #'cider.nrepl/wrap-apropos, see nrepl.middleware/set-descriptor!
[WARNING] No nREPL middleware descriptor in metadata of #'cider.nrepl/wrap-classpath, see nrepl.middleware/set-descriptor!
[WARNING] No nREPL middleware descriptor in metadata of #'cider.nrepl/wrap-complete, see nrepl.middleware/set-descriptor!
[WARNING] No nREPL middleware descriptor in metadata of #'cider.nrepl/wrap-debug, see nrepl.middleware/set-descriptor!
[WARNING] No nREPL middleware descriptor in metadata of #'cider.nrepl/wrap-enlighten, see nrepl.middleware/set-descriptor!
[WARNING] No nREPL middleware descriptor in metadata of #'cider.nrepl/wrap-format, see nrepl.middleware/set-descriptor!
[WARNING] No nREPL middleware descriptor in metadata of #'cider.nrepl/wrap-info, see nrepl.middleware/set-descriptor!
[WARNING] No nREPL middleware descriptor in metadata of #'cider.nrepl/wrap-inspect, see nrepl.middleware/set-descriptor!
[WARNING] No nREPL middleware descriptor in metadata of #'cider.nrepl/wrap-macroexpand, see nrepl.middleware/set-descriptor!
[WARNING] No nREPL middleware descriptor in metadata of #'cider.nrepl/wrap-slurp, see nrepl.middleware/set-descriptor!
[WARNING] No nREPL middleware descriptor in metadata of #'cider.nrepl/wrap-ns, see nrepl.middleware/set-descriptor!
[WARNING] No nREPL middleware descriptor in metadata of #'cider.nrepl/wrap-out, see nrepl.middleware/set-descriptor!
[WARNING] No nREPL middleware descriptor in metadata of #'cider.nrepl/wrap-content-type, see nrepl.middleware/set-descriptor!
[WARNING] No nREPL middleware descriptor in metadata of #'cider.nrepl/wrap-slurp, see nrepl.middleware/set-descriptor!
[WARNING] No nREPL middleware descriptor in metadata of #'cider.nrepl/wrap-pprint, see nrepl.middleware/set-descriptor!
[WARNING] No nREPL middleware descriptor in metadata of #'cider.nrepl/wrap-pprint-fn, see nrepl.middleware/set-descriptor!
[WARNING] No nREPL middleware descriptor in metadata of #'cider.nrepl/wrap-profile, see nrepl.middleware/set-descriptor!
[WARNING] No nREPL middleware descriptor in metadata of #'cider.nrepl/wrap-refresh, see nrepl.middleware/set-descriptor!
[WARNING] No nREPL middleware descriptor in metadata of #'cider.nrepl/wrap-resource, see nrepl.middleware/set-descriptor!
[WARNING] No nREPL middleware descriptor in metadata of #'cider.nrepl/wrap-spec, see nrepl.middleware/set-descriptor!
[WARNING] No nREPL middleware descriptor in metadata of #'cider.nrepl/wrap-stacktrace, see nrepl.middleware/set-descriptor!
[WARNING] No nREPL middleware descriptor in metadata of #'cider.nrepl/wrap-test, see nrepl.middleware/set-descriptor!
[WARNING] No nREPL middleware descriptor in metadata of #'cider.nrepl/wrap-trace, see nrepl.middleware/set-descriptor!
[WARNING] No nREPL middleware descriptor in metadata of #'cider.nrepl/wrap-tracker, see nrepl.middleware/set-descriptor!
[WARNING] No nREPL middleware descriptor in metadata of #'cider.nrepl/wrap-undef, see nrepl.middleware/set-descriptor!
[WARNING] No nREPL middleware descriptor in metadata of #'cider.nrepl/wrap-version, see nrepl.middleware/set-descriptor!
nREPL server started on port 36457 on host 127.0.0.1 - nrepl://127.0.0.1:36457

This means that you’re trying to load middleware incompatible with the current version of nREPL. Make sure you’re using the latest versions of all the middleware libraries in your project/profiles and that you’re not loading any projects with explicit tools.nrepl dependencies that get required early in your projects (e.g. in user.clj).

Leiningen

The REPL Task Crashes

If you experience problems running lein repl you have to make sure that:

  • You’re not using Leiningen 2.8.2 (a bug there rendered the repl task unusable - it was addressed in 2.8.3).

  • Your project is using Clojure 1.7+.

  • Your project is using Java 8+.

  • You’re using the latest versions of nREPL middleware.