Elpy: Error from python-shell-completion-at-point

[mambolevis]

Hi,

The following error appears in the *Python* buffer when it tries any autocompletion.
In [2]: ne
After typing one or two words, this error is shown:

Company: An error occurred in auto-begin
Company: backend (company-capf :with company-yasnippet) error "Invalid search bound (wrong side of point)" with args (prefix)

Any idea how to deal with this issue?
Thanks

[galaunay]

Hi,

I got the same error some months ago.
In my case, it os apparently due to a bug in company, that modify the cursor position before calling python-shell-completion-at-point.

A possible workaround that works for me:

(defadvice python-shell-completion-at-point (before fix-company-bug activate)
  "Fix a bug in company, modifying the current point"
  (goto-char (point-max)))

For a more sustainable solution, you will have to report this to company and/or python.

[mambolevis]

@galaunay
Yes, the workaround works. Thank you.
I reported it in company-mode.
What is the official place (repo) to report it in python?

[galaunay]

Happy that the workaround works for you too,
this shows that there is indeed a problem.

Python-mode is part of Emacs,
so problems with python-mode should be reported directly to emacs.

The best way to do it is by using report-emacs-bug.
You can have more infos on how to properly report an issue by doing report-emacs-bug-info.

If I were you, I'll wait for an answer from company before reporting to emacs.

[mambolevis]

Thank you.
Ok. I will follow your advice.

[galaunay]

Alright,
Thank you for reporting this.

[mambolevis]

I reopen this issue in order to provide a most robust solution according to
https://github.com/company-mode/company-mode/issues/759
I also changed the title for a better reference.

[galaunay]

Thanks for the feedback,
their solution is way better than mine.

I made a PR to be sure this won't bug anyone else.

[mambolevis]

Thank you for answering my very first question, that gave me the opportunity not only to learn but also to explore possible solutions and alternatives.

[mambolevis]

@galaunay
Hi, I updated elpy in order to test your fix https://github.com/jorgenschaefer/elpy/pull/1301/commits/da2bfaf387d5b176f33a11905f5894d0e3879668
Two important conclusions:

• I found a scenario where it fails again: when using company-yasnippet as backend. I needed to come back again to the advice función.
• I played a lot this weekend with my emacs configuration and for any reason company stopped showing candidates in the python-shell buffer . The point is that I did not change my python related configuration.

Elpy Configuration
Virtualenv........: None
RPC Python........: 3.5.4 (c:/Anaconda3/envs/py35/pythonw.exe)
Interactive Python: ipython (c:/Anaconda3/envs/py35/Scripts/ipython.exe)
Emacs.............: 25.3.1
Elpy..............: 1.18.0
Jedi..............: 0.11.1
Rope..............: 0.10.7
Autopep8..........: 1.3.4
Yapf..............: 0.20.2
Syntax checker....: flake8.exe (c:/Anaconda3/envs/py35/Scripts/flake8.exe)

Question: Is your python-shell-completion-at-point still working after your fixe? Bellow my company configuration.

(use-package company
  :ensure t
  :demand
  :preface
  ;;----------------------------------------------------------------------------
  ;;;  Add yasnippet to all company backends
  ;;----------------------------------------------------------------------------
  (defun company-mode/backend-with-yas (backend)
    "Add BACKEND to jasnippet."
    (if (and (listp backend) (member 'company-yasnippet backend))
        backend
      (append (if (consp backend) backend (list backend))
              '(:with company-yasnippet))))
  (eval-after-load "yasnippet"
    '(progn
       (setq company-backends
             (mapcar #'company-mode/backend-with-yas company-backends))))
  ;;----------------------------------------------------------------------------
  :bind
  (:map company-active-map
        ("C-n" . company-select-next)
        ("C-p" . company-select-previous)
        ("RET" . company-complete-common)
        ("<tab>" . company-complete-selection))
  :bind ("C-<tab>" . company-manual-begin)
  :config
  (setq company-minimum-prefix-length 1
        ;;company-tooltip-align-annotations t
        company-idle-delay 0
        company-transformers '(company-sort-by-occurrence)
        )
  (global-company-mode 1))

[galaunay]

I could not reproduce the issue for company-yasnippet, even with your company configuration.
Is it the same error than before ?

python-shell-completion-at-point works for me after the patch.
Does it give you a reason for the failure ?

[mambolevis]

python-shell-completion-at-point works for me after the patch.
Does it give you a reason for the failure ?

No, I even started emacs as (runemacs -Q) and made several tests with different computers and different emacs versions (25,26 including pre-tests and my own build versions) but unfortunately the Shell native completion is disabled. I have already reported that issue.

Question: Which version of emacs, python (Anaconda or any other) and the operating system are you using?

Thanks.

[galaunay]

Emacs 25.3.1,
Python 3.6.4,
on Arch (Linux 4.14).

Does any of the computer you made your tests on is on Linux ?

[mambolevis]

Does any of the computer you made your tests on is on Linux ?

The problem is just my Windows machines. In Linux it works fine.

[galaunay]

Unfortunately, I have no experience in using python-mode on windows.
Hope the guys from python-mode will be more helpful.