Completion-at-point with helm in a python inferior REPL process causes flooding in REPL with autocompletion text

[atreyasha]

Description :octocat:

When executing completion-at-point using helm in a python inferior REPL, the shell (eg. ipython) gets flooded with autocompletion text when the user types or removes text from the helm window.

Reproduction guide :beetle:

• Start Emacs
• Open a python file
• Start a python inferior REPL process
• Import module(s)/object(s) which have potential autocompletions
• Execute autocompletion (for eg. using TAB) of a module/object in the python inferior REPL process
• In the helm completion-at-point popup window, remove some text and then type some extra text (update: this needs to be done quickly)
• Observe the inferior REPL process for any flooding

Observed behaviour: :eyes: :broken_heart:

• The python inferior REPL gets flooded with autocompletion text/possibilities

Expected behaviour: :heart: :smile:

• The python inferior REPL should not get flooded with autocompletion text. It should look exactly the same.
• I tested out the inferior REPL with the ESS layer and this same behaviour is not observed there. So this might be something specific to the python layer.

System Info :computer:

• OS: gnu/linux
• Emacs: 26.3
• Spacemacs: 0.300.0
• Spacemacs branch: develop (rev. 78b45b416)
• Graphic display: t
• Distribution: spacemacs
• Editing style: vim
• Completion: helm
• Layers:

  (bibtex imenu-list ruby html yaml pdf python
      (ess :variables ess-use-flymake nil ess-indent-with-fancy-comments nil)
      helm emacs-lisp
      (markdown :variables markdown-live-preview-engine 'vmd)
      org
      (shell :variables shell-default-height 30 shell-default-position 'bottom)
      (syntax-checking :variables syntax-checking-enable-by-default nil syntax-checking-enable-tooltips nil)
      (latex :variables latex-enable-auto-fill nil latex-enable-magic nil)
      themes-megapack)

• System configuration features: XPM JPEG TIFF GIF PNG RSVG IMAGEMAGICK SOUND GPM DBUS GSETTINGS GLIB NOTIFY ACL GNUTLS LIBXML2 FREETYPE M17N_FLT LIBOTF XFT ZLIB TOOLKIT_SCROLL_BARS GTK3 X11 XDBE XIM MODULES THREADS LIBSYSTEMD LCMS2

Backtrace :paw_prints:

<<BACKTRACE IF RELEVANT>>

If it helps, I can also produce/upload a gif of the observed behaviour. Otherwise, below is a screenshot of what the autocompletion text flooding looks like:

[cmatzenbach]

This doesn't happen in SLIME (Common Lisp repl) either, so it does look specific to this layer. Unfortunately I don;t know python, I can take a look at the layer files but it would seem to be some setting/bug from the auto-completion, maybe helm. I think the quickest test you could run is to switch to ivy and see if it still happens - that should give us more info on where the bug is.

[alexey0308]

As I understand, ipython completion is treated differently in python.el emacs file. I observe the issue only if one types quickly in the helm window, i.e. add a new symbol while the suggestion-list is being updated. It seems to be an issue with the python-mode. Does it help, if one removes "ipython" in python-shell-completion-native-disabled-interpreters by customize-variable, or if one uses python instead of ipython (SPC-u C-c C-p python)?

Alternatively, one may use helm-company instead of completion-at-point (bound to C-/ when company-mode is activated in the inferior-buffer and after company suggestion window has appeared).

[atreyasha]

Hi @cmatzenbach @alexey0308, thank you both for the quick responses. Regarding your suggestions:

1. @cmatzenbach, I tried switching to ivy and this problem goes away. So this must have something to do with an interaction between python.el and helm.

2. @alexey0308, removing ipython from python-shell-completion-native-disabled-interpreters or working directly in a python shell resulted in this issue going away. I am not entirely sure why this helps, any perspectives? Do you think removing ipython from the above-mentioned list could lead to problems downstream?

I disabled company-mode because it conflicts with some other private layers, so helm-company would probably not be a workaround for my use-case. But yes, helm-company could definitely be a workaround for users who use company-mode actively.

[alexey0308]

I am not entirely sure why this helps, any perspectives?

I do not know, how all this functions, but the following change might be related to the reason, why ipython was added to the list. Although there was provided --simple-prompt flag for compatibility. But it is just a guess, and I can not say anything about downstream due to lack of knowledge. Hope it helps.

[atreyasha]

@alexey0308 no worries at all, thank you for sharing this information, it is very much appreciated :heart:

Just to conclude, I added the following under my dotspacemacs/user-config to resolve the issue (in case it is of help to other users who use ipython as their python inferior REPL):

(eval-after-load 'python
  '(setq python-shell-completion-native-disabled-interpreters
         (delete "ipython" python-shell-completion-native-disabled-interpreters)))

With that, will close this issue.