Backspace not working + Documentation-help is broken (Edit 3+ gif)

[DavidCdeB]

Issue Description (Edited 3 + gif)

Here I provide an updated gif narrowing down the whole problem:

Steps:

1. Open an empty file with vim.
2. Start writing: import numpy as np
3. New line: a = np.arr
4. You see the doc appears somehow broken...
5. I select "array"
6. Part of the doc info has sticked there
7. I finish the statement: a = np.array(x)
8. Once created the last ), I create a new line by pressing ENTER key
9. I am still in INSERT mode, I am pressing BACKSPACE, but it does not erase the content of the line or any other line.
10. I go to the documentation splitted window, by pressing ESC, and Ctrl W W
11. I quit, pressing :q
12. docu window closes ok
13. I am now again in INSERT mode, I am pressing BACKSPACE, but it does not erase the content of the line or any other line

The documentation seems broken:

Issue Details

• What did I do?

  
  $ cd ~/.vim/bundle
  $ git clone git@github.com:ycm-core/YouCompleteMe.git
  $ cd ~/.vim/bundle/YouCompleteMe
  $ git submodule update --init --recursive
  $ ./install.py

everything went well, output here:

Searching Python 3.7 libraries... Found Python library: /home/modules/software/Python/3.7.4-GCCcore-8.3.0/lib/libpython3.7m.so Found Python headers folder: /home/modules/software/Python/3.7.4-GCCcore-8.3.0/include/python3.7m -- The C compiler identification is GNU 8.3.0 -- The CXX compiler identification is GNU 8.3.0 -- Check for working C compiler: /home/modules/software/GCCcore/8.3.0/bin/cc -- Check for working C compiler: /home/modules/software/GCCcore/8.3.0/bin/cc -- works -- Detecting C compiler ABI info -- Detecting C compiler ABI info - done -- Detecting C compile features -- Detecting C compile features - done -- Check for working CXX compiler: /home/modules/software/GCCcore/8.3.0/bin/c++ -- Check for working CXX compiler: /home/modules/software/GCCcore/8.3.0/bin/c++ -- works -- Detecting CXX compiler ABI info -- Detecting CXX compiler ABI info - done -- Detecting CXX compile features -- Detecting CXX compile features - done -- Found PythonLibs: /home/modules/software/Python/3.7.4-GCCcore-8.3.0/lib/libpython3.7m.so (found suitable version "3.7.4", minimum required is "3.5") -- NOT using libclang, no semantic completion for C/C++/ObjC will be available -- NOT using clang-tidy for static analysis. -- Configuring done -- Generating done -- Build files have been written to: /tmp/ycm_build_b7f53_qj Scanning dependencies of target BoostParts [ 2%] Building CXX object BoostParts/CMakeFiles/BoostParts.dir/libs/filesystem/src/codecvt_error_category.cpp.o [ 4%] Building CXX object BoostParts/CMakeFiles/BoostParts.dir/libs/filesystem/src/operations.cpp.o [ 7%] Building CXX object BoostParts/CMakeFiles/BoostParts.dir/libs/filesystem/src/unique_path.cpp.o [ 9%] Building CXX object BoostParts/CMakeFiles/BoostParts.dir/libs/filesystem/src/path.cpp.o [ 11%] Building CXX object BoostParts/CMakeFiles/BoostParts.dir/libs/filesystem/src/portability.cpp.o [ 14%] Building CXX object BoostParts/CMakeFiles/BoostParts.dir/libs/filesystem/src/path_traits.cpp.o [ 16%] Building CXX object BoostParts/CMakeFiles/BoostParts.dir/libs/filesystem/src/utf8_codecvt_facet.cpp.o [ 19%] Building CXX object BoostParts/CMakeFiles/BoostParts.dir/libs/filesystem/src/windows_file_codecvt.cpp.o [ 21%] Building CXX object BoostParts/CMakeFiles/BoostParts.dir/libs/regex/src/cregex.cpp.o [ 23%] Building CXX object BoostParts/CMakeFiles/BoostParts.dir/libs/regex/src/c_regex_traits.cpp.o [ 26%] Building CXX object BoostParts/CMakeFiles/BoostParts.dir/libs/regex/src/fileiter.cpp.o [ 28%] Building CXX object BoostParts/CMakeFiles/BoostParts.dir/libs/regex/src/icu.cpp.o [ 30%] Building CXX object BoostParts/CMakeFiles/BoostParts.dir/libs/regex/src/cpp_regex_traits.cpp.o [ 33%] Building CXX object BoostParts/CMakeFiles/BoostParts.dir/libs/regex/src/posix_api.cpp.o [ 38%] Building CXX object BoostParts/CMakeFiles/BoostParts.dir/libs/regex/src/regex.cpp.o [ 38%] Building CXX object BoostParts/CMakeFiles/BoostParts.dir/libs/regex/src/instances.cpp.o [ 40%] Building CXX object BoostParts/CMakeFiles/BoostParts.dir/libs/regex/src/regex_traits_defaults.cpp.o [ 42%] Building CXX object BoostParts/CMakeFiles/BoostParts.dir/libs/regex/src/regex_debug.cpp.o [ 45%] Building CXX object BoostParts/CMakeFiles/BoostParts.dir/libs/regex/src/w32_regex_traits.cpp.o [ 47%] Building CXX object BoostParts/CMakeFiles/BoostParts.dir/libs/regex/src/regex_raw_buffer.cpp.o [ 50%] Building CXX object BoostParts/CMakeFiles/BoostParts.dir/libs/regex/src/static_mutex.cpp.o [ 52%] Building CXX object BoostParts/CMakeFiles/BoostParts.dir/libs/regex/src/usinstances.cpp.o [ 54%] Building CXX object BoostParts/CMakeFiles/BoostParts.dir/libs/regex/src/wide_posix_api.cpp.o [ 57%] Building CXX object BoostParts/CMakeFiles/BoostParts.dir/libs/regex/src/wc_regex_traits.cpp.o [ 59%] Building CXX object BoostParts/CMakeFiles/BoostParts.dir/libs/regex/src/winstances.cpp.o [ 61%] Linking CXX static library libBoostParts.a [ 61%] Built target BoostParts Scanning dependencies of target ycm_core [ 64%] Building CXX object ycm/CMakeFiles/ycm_core.dir/Candidate.cpp.o [ 66%] Building CXX object ycm/CMakeFiles/ycm_core.dir/Character.cpp.o [ 69%] Building CXX object ycm/CMakeFiles/ycm_core.dir/IdentifierCompleter.cpp.o [ 73%] Building CXX object ycm/CMakeFiles/ycm_core.dir/CodePointRepository.cpp.o [ 73%] Building CXX object ycm/CMakeFiles/ycm_core.dir/CandidateRepository.cpp.o [ 76%] Building CXX object ycm/CMakeFiles/ycm_core.dir/CodePoint.cpp.o [ 78%] Building CXX object ycm/CMakeFiles/ycm_core.dir/CharacterRepository.cpp.o [ 80%] Building CXX object ycm/CMakeFiles/ycm_core.dir/IdentifierDatabase.cpp.o [ 83%] Building CXX object ycm/CMakeFiles/ycm_core.dir/IdentifierUtils.cpp.o [ 85%] Building CXX object ycm/CMakeFiles/ycm_core.dir/versioning.cpp.o [ 88%] Building CXX object ycm/CMakeFiles/ycm_core.dir/PythonSupport.cpp.o [ 90%] Building CXX object ycm/CMakeFiles/ycm_core.dir/ycm_core.cpp.o [ 92%] Building CXX object ycm/CMakeFiles/ycm_core.dir/Utils.cpp.o [ 95%] Building CXX object ycm/CMakeFiles/ycm_core.dir/Word.cpp.o [ 97%] Building CXX object ycm/CMakeFiles/ycm_core.dir/Result.cpp.o [100%] Linking CXX shared library /home/energy/dcabu/.vim/bundle/YouCompleteMe/third_party/ycmd/ycm_core.so [100%] Built target ycm_core -- The C compiler identification is GNU 8.3.0 -- Check for working C compiler: /home/modules/software/GCCcore/8.3.0/bin/cc -- Check for working C compiler: /home/modules/software/GCCcore/8.3.0/bin/cc -- works -- Detecting C compiler ABI info -- Detecting C compiler ABI info - done -- Detecting C compile features -- Detecting C compile features - done -- Found PythonLibs: /home/modules/software/Python/3.7.4-GCCcore-8.3.0/lib/libpython3.7m.so (found version "3.7.4") -- Configuring done -- Generating done -- Build files have been written to: /tmp/regex_buildgc0mc24 Scanning dependencies of target _regex [ 33%] Building C object CMakeFiles/_regex.dir/regex_3/_regex.c.o [ 66%] Building C object CMakeFiles/_regex.dir/regex_3/_regex_unicode.c.o [100%] Linking C shared library /home/energy/dcabu/.vim/bundle/YouCompleteMe/third_party/ycmd/third_party/cregex/regex_3/_regex.so [100%] Built target _regex

## Output of `YcmDebugInfo` and `:scriptnames`

$ which vim /home/modules/software/Vim/8.2-GCCcore-8.3.0-Python-3.7.4/bin/vim $ vim ~/filename.py :YcmDebugInfo

Printing YouCompleteMe debug information... -- Client logfile: /tmp/ycm_kz5js46m.log -- Server Python interpreter: /home/modules/software/Python/3.7.4-GCCcore-8.3.0/bin/python3 -- Server Python version: 3.7.4 -- Server has Clang support compiled in: False -- Clang version: None -- No extra configuration file found -- Python completer debug information: -- Python interpreter: /home/modules/software/Python/3.7.4-GCCcore-8.3.0/bin/python3 -- Python path: ['/home/modules/software/ASE/3.19.0-intel-2019b-Python-3.7.4/lib/python3.7/site-packa ges', '/home/modules/software/matplotlib/3.1.1-intel-2019b-Python-3.7.4/lib/python3.7/site-packages', ' /home/modules/software/Tkinter/3.7.4-GCCcore-8.3.0/lib/python3.7', '/home/modules/software/Tkinter/3.7. 4-GCCcore-8.3.0/easybuild/python', '/home/modules/software/SciPy-bundle/2019.10-intel-2019b-Python-3.7. 4/lib/python3.7/site-packages', '/home/modules/software/Python/3.7.4-GCCcore-8.3.0/easybuild/python', ' /home/modules/software/IPython/7.2.0-intel-2018b-Python-3.6.6/lib/python3.6/site-packages', '/home/modu les/software/Python/3.7.4-GCCcore-8.3.0/lib/python37.zip', '/home/modules/software/Python/3.7.4-GCCcore -8.3.0/lib/python3.7', '/home/modules/software/Python/3.7.4-GCCcore-8.3.0/lib/python3.7/lib-dynload', ' /home/energy/dcabu/.local/lib/python3.7/site-packages', '/home/modules/software/Python/3.7.4-GCCcore-8. 3.0/lib/python3.7/site-packages', '/home/modules/software/Python/3.7.4-GCCcore-8.3.0/lib/python3.7/site -packages/pip-19.2.3-py3.7.egg'] -- Python version: 3.7.4 -- Jedi version: 0.16.0 -- Parso version: 0.6.1 -- Server running at: http://127.0.0.1:38907 -- Server process ID: 18160 -- Server logfiles: -- /tmp/ycmd_38907_stdout_mwome_7c.log -- /tmp/ycmd_38907_stderr_lrc07ybn.log

:scriptnames 1: ~/.vimrc 2: /home/modules/software/Vim/8.2-GCCcore-8.3.0-Python-3.7.4/share/vim/vim82/syntax/syntax.vim 3: /home/modules/software/Vim/8.2-GCCcore-8.3.0-Python-3.7.4/share/vim/vim82/syntax/synload.vim 4: /home/modules/software/Vim/8.2-GCCcore-8.3.0-Python-3.7.4/share/vim/vim82/syntax/syncolor.vim 5: /home/modules/software/Vim/8.2-GCCcore-8.3.0-Python-3.7.4/share/vim/vim82/filetype.vim 6: /home/modules/software/Vim/8.2-GCCcore-8.3.0-Python-3.7.4/share/vim/vim82/ftplugin.vim 7: /home/modules/software/Vim/8.2-GCCcore-8.3.0-Python-3.7.4/share/vim/vim82/indent.vim 8: ~/.vim/autoload/pathogen.vim 9: /home/modules/software/Vim/8.2-GCCcore-8.3.0-Python-3.7.4/share/vim/vim82/ftoff.vim 10: ~/.vim/bundle/YouCompleteMe/plugin/youcompleteme.vim 11: /home/modules/software/Vim/8.2-GCCcore-8.3.0-Python-3.7.4/share/vim/vim82/plugin/getscriptPlugin.v im 12: /home/modules/software/Vim/8.2-GCCcore-8.3.0-Python-3.7.4/share/vim/vim82/plugin/gzip.vim 13: /home/modules/software/Vim/8.2-GCCcore-8.3.0-Python-3.7.4/share/vim/vim82/plugin/logiPat.vim 14: /home/modules/software/Vim/8.2-GCCcore-8.3.0-Python-3.7.4/share/vim/vim82/plugin/manpager.vim 15: /home/modules/software/Vim/8.2-GCCcore-8.3.0-Python-3.7.4/share/vim/vim82/plugin/matchparen.vim 16: /home/modules/software/Vim/8.2-GCCcore-8.3.0-Python-3.7.4/share/vim/vim82/plugin/netrwPlugin.vim 17: /home/modules/software/Vim/8.2-GCCcore-8.3.0-Python-3.7.4/share/vim/vim82/plugin/rrhelper.vim 18: /home/modules/software/Vim/8.2-GCCcore-8.3.0-Python-3.7.4/share/vim/vim82/plugin/spellfile.vim 19: /home/modules/software/Vim/8.2-GCCcore-8.3.0-Python-3.7.4/share/vim/vim82/plugin/tarPlugin.vim 20: /home/modules/software/Vim/8.2-GCCcore-8.3.0-Python-3.7.4/share/vim/vim82/plugin/tohtml.vim 21: /home/modules/software/Vim/8.2-GCCcore-8.3.0-Python-3.7.4/share/vim/vim82/plugin/vimballPlugin.vim

22: /home/modules/software/Vim/8.2-GCCcore-8.3.0-Python-3.7.4/share/vim/vim82/plugin/zipPlugin.vim 23: ~/.vim/bundle/indentLine/after/plugin/indentLine.vim 24: /home/modules/software/Vim/8.2-GCCcore-8.3.0-Python-3.7.4/share/vim/vim82/syntax/python.vim 25: /home/modules/software/Vim/8.2-GCCcore-8.3.0-Python-3.7.4/share/vim/vim82/ftplugin/python.vim 26: /home/modules/software/Vim/8.2-GCCcore-8.3.0-Python-3.7.4/share/vim/vim82/indent/python.vim 27: ~/.vim/bundle/YouCompleteMe/autoload/youcompleteme.vim 28: /home/modules/software/Vim/8.2-GCCcore-8.3.0-Python-3.7.4/share/vim/vim82/syntax/vim.vim 29: /home/modules/software/Vim/8.2-GCCcore-8.3.0-Python-3.7.4/share/vim/vim82/syntax/perl.vim 30: /home/modules/software/Vim/8.2-GCCcore-8.3.0-Python-3.7.4/share/vim/vim82/syntax/pod.vim 31: /home/modules/software/Vim/8.2-GCCcore-8.3.0-Python-3.7.4/share/vim/vim82/ftplugin/vim.vim 32: /home/modules/software/Vim/8.2-GCCcore-8.3.0-Python-3.7.4/share/vim/vim82/indent/vim.vim

## Output of `vim --version`

$ vim --version
VIM - Vi IMproved 8.2 (2019 Dec 12, compiled Feb 26 2020 09:59:41) Compiled by root@svol.fysik.dtu.dk Huge version without GUI. Features included (+) or not (-): +acl -farsi -mouse_sysmouse -tag_old_static +arabic +file_in_path +mouse_urxvt -tag_any_white +autocmd +find_in_path +mouse_xterm -tcl +autochdir +float +multi_byte +termguicolors -autoservername +folding +multi_lang +terminal -balloon_eval -footer -mzscheme +terminfo +balloon_eval_term +fork() +netbeans_intg +termresponse -browse +gettext +num64 +textobjects ++builtin_terms -hangul_input +packages +textprop +byte_offset +iconv +path_extra +timers +channel +insert_expand +perl +title +cindent +job +persistent_undo -toolbar -clientserver +jumplist +popupwin +user_commands -clipboard +keymap +postscript +vartabs +cmdline_compl +lambda +printer +vertsplit +cmdline_hist +langmap +profile +virtualedit +cmdline_info +libcall -python +visual +comments +linebreak +python3 +visualextra +conceal +lispindent +quickfix +viminfo +cryptv +listcmds +reltime +vreplace +cscope +localmap +rightleft +wildignore +cursorbind -lua -ruby +wildmenu +cursorshape +menu +scrollbind +windows +dialog_con +mksession +signs +writebackup +diff +modify_fname +smartindent -X11 +digraphs +mouse -sound -xfontset -dnd -mouseshape +spell -xim -ebcdic +mouse_dec +startuptime -xpm +emacs_tags -mouse_gpm +statusline -xsmp +eval -mouse_jsbterm -sun_workshop -xterm_clipboard +ex_extra +mouse_netterm +syntax -xterm_save +extra_search +mouse_sgr +tag_binary system vimrc file: "$VIM/vimrc" user vimrc file: "$HOME/.vimrc" 2nd user vimrc file: "~/.vim/vimrc" user exrc file: "$HOME/.exrc" defaults file: "$VIMRUNTIME/defaults.vim" fall-back for $VIM: " /home/modules/software/Vim/8.2-GCCcore-8.3.0-Python-3.7.4/share/vim" Compilation: gcc -c -I. -Iproto -DHAVE_CONFIG_H -I/home/modules/software/PCRE/8.43-GCCcore-8.3.0/include -I/home/modules/software/Python/3.7.4-GCCcore-8.3.0/include -I/home/modules/software/binutils/2.32-GCCcore-8.3.0/include -I/usr/local/include -O2 -ftree-vectorize -march=native -fno-math-errno -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=1 Linking: gcc -Wl,-E -L/home/modules/software/PCRE/8.43-GCCcore-8.3.0/lib -L/home/modules/software/Perl/5.30.0-GCCcore-8.3.0/lib -L/home/modules/software/Python/3.7.4-GCCcore-8.3.0/lib -L/home/modules/software/binutils/2.32-GCCcore-8.3.0/lib -L/home/modules/software/GCCcore/8.3.0/lib64 -L/home/modules/software/GCCcore/8.3.0/lib -L/usr/local/lib -Wl,--as-needed -o vim -lm -ltinfo -lnsl -lm -lpthread -lselinux -ldl -Wl,-E -fstack-protector-strong -L/usr/local/lib -L/home/modules/software/Perl/5.30.0-GCCcore-8.3.0/lib/perl5/5.30.0/x86_64-linux-thread-multi/CORE -lperl -lpthread -lnsl -ldl -lm -lcrypt -lutil -lc -L/home/modules/software/Python/3.7.4-GCCcore-8.3.0/lib/python3.7/config-3.7m-x86_64-linux-gnu -lpython3.7m -lcrypt -ldl -lm -lpthread -lutil -lm

## OS version, distribution, etc.

$ lsb_release -a LSB Version: :core-4.1-amd64:core-4.1-noarch Distributor ID: CentOS Description: CentOS Linux release 7.7.1908 (Core) Release: 7.7.1908 Codename: Core

## vimrc:

" Tell vim to remember certain things when we exit " '10 : marks will be remembered for up to 10 previously edited files " "100 : will save up to 100 lines for each register " :20 : up to 20 lines of command-line history will be remembered " % : saves and restores the buffer list " n... : where to save the viminfo files set viminfo='10,\"100,:20,%,n~/.viminfo

function! ResCur() if line("'\"") <= line("$") normal! g`" return 1 endif endfunction

augroup resCur autocmd! autocmd BufWinEnter * call ResCur() augroup END

syntax on

filetype plugin on filetype indent on

" to disable pathogen plugins: https://til.hashrocket.com/posts/17d6887175-disable-a-pathogen-plugin let g:pathogen_disabled = [] call add(g:pathogen_disabled, 'indentLine')

" pathogen is a vim plugin manager. Install it via pacman -Ss vim-pathogen execute pathogen#infect()

set tabstop =4 set softtabstop =4 set shiftwidth =4 set expandtab

set cursorline hi cursorline cterm=none term=none :highlight CursorLine ctermbg=LightGray

autocmd BufEnter .tex setlocal conceallevel=0 autocmd BufEnter .tex setlocal concealcursor=

[bstaletic]

Can you try with no plugins enabled, except for YCM? That would eliminate the possibility of conflict with another plugin.

[DavidCdeB]

@bstaletic The only other plugin I have is indentLine. I have disabled it. I have pasted the ~./vimrc above (it's very short). The backspace does not work, for instance when having typed that line, creating a new line and then going back to the previous line, to start deleting from ). Moreover, the documentation appears broken (see image, edited post)

[puremourning]

Thanks for the detailed report.

In order for us to reproduce, please can you:

• test with the following vimrc (save as vimrc_ycm_minimal and run vim -Nu vimrc_ycm_minimal), replace /path/to/YCM:

set rtp+=/path/to/YCM
filetype plugin indent on

• provide exact instructions to repro, in the form of a list of instructions, such as:
  • run vim -Nu vimrc_ycm_minimal
  • enter insert mode
  • type <characters ...>
  • etc.

[puremourning]

Something is odd about your vim --version output. It doesn't include the patch number.

The display issues are likely vim bugs (nothing that YCM can do about it) and I can't repro them on the latest vim patch.

I also can't repro the backspace issue, but I have a suspicion that you're just not in insert mode after closing the preview window. THat's why I wanted the exact steps.

[DavidCdeB]

@puremourning Many thanks for your comments.

I also can't repro the backspace issue, but I have a suspicion that you're just not in insert mode after closing the preview window. THat's why I wanted the exact steps.

Unfortunately the old gif capture did not show the bottom of the terminal, which read I was indeed in INSERT mode

Please find a much more detailed gif + exact description in the new edited post

[DavidCdeB]

set rtp+=/path/to/YCM
filetype plugin indent on

@puremourning: Does /path/to/YCM points to where youcompleteme.vim is located?

I have tried the following three:

1. set rtp+=/home/energy/dcabu/.vim/bundle/YouCompleteMe/autoload/youcompleteme.vim

2. set rtp+=/home/energy/dcabu/.vim/bundle/YouCompleteMe/autoload

3. set rtp+=/home/energy/dcabu/.vim/bundle/YouCompleteMe

For the three cases, I have done vim -Nu vimrc_ycm_minimal but I receive this error: E282: Cannot read from "vimrc_ycm_minimal" Press ENTER or type command to continue

[puremourning]

set rtp+=/home/energy/dcabu/.vim/bundle/YouCompleteMe

That one

Cannot read from "vimrc_ycm_minimal" Press ENTER or type command to continue

You need to write those two lines to a new file and save it as ‘vimrc_ycm_minimal‘. I thought that was obvious.

[DavidCdeB]

@puremourning Many thanks and sorry about that.

I save those lines into a new file:

[dcabu@svol ~]$ cat vimrc_ycm_minimal 
set rtp+=/home/energy/dcabu/.vim/bundle/YouCompleteMe
filetype plugin indent on

Then I follow the following steps, see the following gif:

1. [dcabu@svol ~]$ vim -Nu vimrc_ycm_minimal example.py
2. I write: import numpy as np. I see that numpy appears a suggestion (I guess because it has been written two words ago)
3. Press ENTER twice
4. I am trying to BACKSPACE, but it does not work
5. Additionally, I write: a = np.arr I see no menu of options (see below gif)

[bstaletic]

Neither of the issues are bugs.

For backspace, see :h 'backspace'.

The missing completions are just because you didn't give jedi enough time to process a giant library. Wait a bit and force completion again.

[DavidCdeB]

@bstaletic

Thank you. Still completion is missing, see this gif:

1. Note I am recording the keys and clicks in the bottom.
2. cat vimrc_ycm_minimal shows the file
3. vim -Nu vimrc_ycm_minimal example.py
4. I write import numpy as np
5. I just press ENTER twice
6. I am trying to BACKSPACE, but it does not work.
7. I do :set backspace=2
8. now BACKSPACE works
9. I write: a = np.ar and no completion is suggested...
10. New declaration c = np.arr ... still nothing suggested

[bstaletic]

I'm still saying that you need to (probably) give jedi more time. Also, the key word in my previous post was force (semantic completion), i.e. in place. Numpy is giant and it takes time for jedi to process everything.

[puremourning]

I just press ENTER twice I am trying to BACKSPACE, but it does not work. I do :set backspace=2 now BACKSPACE works

Well, yeah. Nothing to do with YCM.

I write: a = np.ar and no completion is suggested...

Either:

• jedi was taking some time to provide the suggestions (it takes a long time for numpy cos it is huge), or
• numpy wasn't available inside the python interpreter environment used by jedi. check the README for (e.g.) how to set up the sys path and/or use a virtualenv.

Either way, this is not a YCM bug, more a support/setup issue, so closing,

If you still can't get it to work, see README about how to contact us for support.