Starting a cider REPL freezes emacs after emidje installation

[aguerra]

Hi everyone,

I'm using ubuntu 18.04 with the standard emacs package (25.2) and if add the following lines to init.el:

(use-package emidje
  :ensure t
  :init
  (eval-after-load 'cider #'emidje-setup))

and start a cider REPL, emacs freezes. I'm using a fresh install (melpa stable) without pinning any versions. Using the emacs echoed lein command line on the shell I get these warnings:

[WARNING] No nREPL middleware descriptor in metadata of #'midje-nrepl.nrepl/wrap-format, see
nrepl.middleware/set-descriptor!
[WARNING] No nREPL middleware descriptor in metadata of #'midje-nrepl.nrepl/wrap-inhibit-tests, see
nrepl.middleware/set-descriptor!
[WARNING] No nREPL middleware descriptor in metadata of #'midje-nrepl.nrepl/wrap-test, see
nrepl.middleware/set-descriptor!
[WARNING] No nREPL middleware descriptor in metadata of #'midje-nrepl.nrepl/wrap-test-info, see
nrepl.middleware/set-descriptor!
[WARNING] No nREPL middleware descriptor in metadata of #'midje-nrepl.nrepl/wrap-version, see
nrepl.middleware/set-descriptor!

[alan-ghelardi]

@aguerra which version of Cider are you using and how are you starting the REPL (via cider-jack-in or cider-connect)?

[alan-ghelardi]

I've reproduced the issue after upgrading to Cider 0.20.0. In fact, I hadn't had time to bump cider-nrepl on midje-nrepl (there were some breaking changes specially in the compatibility with org.clojure/tools.nrepl), but the problem that you reported is related to this version.
I've started working on the fix. For now, you can disable the nREPL injection by setting emidje-inject-nrepl-middleware-at-jack-in to nil:

(use-package emidje
  :ensure t
  :init
  (setq emidje-inject-nrepl-middleware-at-jack-in nil)
  :config
  (eval-after-load 'cider
    #'emidje-setup))

Alternatively, you can disable the middleware entirely for now:

(use-package emidje
  :ensure t)

Thanks for catching this one.

[alan-ghelardi]

@aguerra I've published a new snapshot version of midje-nrepl with the fix. If you start the REPL via cider-jack-in everything should work normally. Thank you again for opening the issue.