neovim/runtime/doc/faq.txt

*faq.txt*		 Nvim

                            NVIM REFERENCE MANUAL


Frequently asked Questions                                        *faq*

                                  Type |gO| to see the table of contents.

==============================================================================
General Questions                                                 *faq-general*


WHERE SHOULD I PUT MY CONFIG (VIMRC)? ~

See |config|; you can copy (or symlink) your existing vimrc. |nvim-from-vim|


HOW STABLE IS THE DEVELOPMENT (PRE-RELEASE) VERSION? ~

The unstable (pre-release)
https://github.com/neovim/neovim/releases/tag/nightly version of Nvim
("HEAD", i.e. the `master` branch) is used to aggressively stage new features
and changes. It's usually stable, but will occasionally break your workflow.
We depend on HEAD users to report "blind spots" that were not caught by
automated tests.

Use the stable (release) https://github.com/neovim/neovim/releases/latest
version for a more predictable experience.


CAN I USE RUBY-BASED VIM PLUGINS (E.G. LUSTYEXPLORER)? ~

Yes, starting with Nvim 0.1.5 PR #4980
https://github.com/neovim/neovim/pull/4980 the legacy Vim `if_ruby` interface
is supported.


CAN I USE LUA-BASED VIM PLUGINS (E.G. NEOCOMPLETE)? ~

No. Starting with Nvim 0.2 PR #4411
https://github.com/neovim/neovim/pull/4411 Lua is built-in, but the legacy
Vim `if_lua` interface is not supported.


HOW CAN I USE "TRUE COLOR" IN THE TERMINAL? ~

Truecolor (24bit colors) are enabled by default if a supporting terminal is
detected. If your terminal is not detected but you are sure it supports
truecolor, add this to your |init.vim|:
>vim
    set termguicolors
<

NVIM SHOWS WEIRD SYMBOLS (`<60>[2 q`) WHEN CHANGING MODES ~

This is a bug in your terminal emulator. It happens because Nvim sends
cursor-shape termcodes by default, if the terminal appears to be
xterm-compatible (`TERM=xterm-256color`).

To workaround the issue, you can:

- Use a different terminal emulator
- Disable 'guicursor' in your Nvim config: >vim

    :set guicursor=
    " Workaround some broken plugins which set guicursor indiscriminately.
    :autocmd OptionSet guicursor noautocmd set guicursor=
<
See also |$TERM| for recommended values of `$TERM`.


HOW TO CHANGE CURSOR SHAPE IN THE TERMINAL? ~

- For Nvim 0.1.7 or older: see the note about `NVIM_TUI_ENABLE_CURSOR_SHAPE` in `man nvim`.
- For Nvim 0.2 or newer: cursor styling is controlled by the 'guicursor' option.
    - To _disable_ cursor-styling, set 'guicursor' to empty: >vim

            :set guicursor=
            " Workaround some broken plugins which set guicursor indiscriminately.
            :autocmd OptionSet guicursor noautocmd set guicursor=
<
    - If you want a non-blinking cursor, use `blinkon0`. See 'guicursor'.
    - 'guicursor' is enabled by default, unless Nvim thinks your terminal doesn't
        support it. If you're sure that your terminal supports cursor-shaping, set
        'guicursor' in your |init.vim|, as described in 'guicursor'.
- The Vim terminal options |t_SI| and `t_EI` are ignored, like all other |t_xx| options.
- Old versions of libvte (gnome-terminal, roxterm, terminator, ...) do not
  support cursor style control codes. #2537
  https://github.com/neovim/neovim/issues/2537


HOW TO CHANGE CURSOR COLOR IN THE TERMINAL? ~

Cursor styling (shape, color, behavior) is controlled by 'guicursor', even in
the terminal. Cursor color (as opposed to shape) only works if
'termguicolors' is set.

'guicursor' gives an example, but here's a more complicated example
which sets different colors in insert-mode and normal-mode:
>vim
    :set termguicolors
    :hi Cursor guifg=green guibg=green
    :hi Cursor2 guifg=red guibg=red
    :set guicursor=n-v-c:block-Cursor/lCursor,i-ci-ve:ver25-Cursor2/lCursor2,r-cr:hor20,o:hor50
<

CURSOR STYLE ISN'T RESTORED AFTER EXITING OR SUSPENDING AND RESUMING NVIM ~

Terminals do not provide a way to query the cursor style. Use autocommands to
manage the cursor style:
>vim
    au VimEnter,VimResume * set guicursor=n-v-c:block,i-ci-ve:ver25,r-cr:hor20,o:hor50
      \,a:blinkwait700-blinkoff400-blinkon250-Cursor/lCursor
      \,sm:block-blinkwait175-blinkoff150-blinkon175

    au VimLeave,VimSuspend * set guicursor=a:block-blinkon0
<

CURSOR SHAPE DOESN'T CHANGE IN TMUX ~

tmux decides that, not Nvim. See |tui-cursor-shape| for a fix.

See #3165 https://github.com/neovim/neovim/pull/3165 for discussion.


CURSOR FLICKER IN TMUX? ~

If cursor `_` appears and disappears very quickly when opening nvim without a
document under tmux, and you set |ctermbg| in `EndOfBuffer` and `Normal`, try
setting these to `NONE`:
>vim
    hi EndOfBuffer ctermbg=NONE ctermfg=200 cterm=NONE
    hi Normal ctermbg=NONE ctermfg=200 cterm=NONE
<

WHAT HAPPENED TO --remote AND FRIENDS? ~

|--remote| is partly supported. |clientserver|

If you require flags from Vim that are missing in Nvim, you can use
https://github.com/mhinz/neovim-remote instead.

==============================================================================
Runtime issues                                                *faq-runtime*


COPYING TO X11 PRIMARY SELECTION WITH THE MOUSE DOESN'T WORK ~

`clipboard=autoselect` is not implemented yet
https://github.com/neovim/neovim/issues/2325. You may find this workaround to
be useful:
>vim
    vnoremap <LeftRelease> "*ygv
    vnoremap <2-LeftRelease> "*ygv
<

MY CTRL-H MAPPING DOESN'T WORK ~

This was fixed in Nvim 0.2. If you are running Nvim 0.1.7 or older,
adjust your terminal's "kbs" (key_backspace) terminfo entry:
>vim
    infocmp $TERM | sed 's/kbs=^[hH]/kbs=\\177/' > $TERM.ti
    tic $TERM.ti
<
(Feel free to delete the temporary `*.ti` file created after running the above
commands).


<HOME> OR SOME OTHER "SPECIAL" KEY DOESN'T WORK ~

Make sure |$TERM| is set correctly.

- For screen or tmux, `$TERM` should be `screen-256color` (not `xterm-256color`!)
- In other cases if "256" does not appear in the string it's probably wrong.
  Try `TERM=xterm-256color`.


:! AND SYSTEM() DO WEIRD THINGS WITH INTERACTIVE PROCESSES ~

Interactive commands are supported by |:terminal| in Nvim. But |:!| and
|system()| do not support interactive commands, primarily because Nvim UIs use
stdio for msgpack communication, but also for performance, reliability, and
consistency across platforms (see
https://vimhelp.org/gui_x11.txt.html#gui-pty).

See also #1496 https://github.com/neovim/neovim/issues/1496 and #8217
https://github.com/neovim/neovim/issues/8217#issuecomment-402152307.


PYTHON SUPPORT ISN'T WORKING ~

Run |:checkhealth| in Nvim for automatic diagnosis.

Other hints:

- The python `neovim` module was renamed to `pynvim` (long ago).
- If you're using pyenv or virtualenv for the `pynvim` module
    https://pypi.python.org/pypi/pynvim/, you must set `g:python3_host_prog` to
    the virtualenv's interpreter path.
- Read |provider-python|.
- Be sure you have the latest version of the `pynvim` Python module: >bash

    python -m pip install setuptools
    python -m pip install --upgrade pynvim
    python3 -m pip install --upgrade pynvim
<
- Try with `nvim -u NORC` to make sure your config (|init.vim|) isn't causing a
    problem. If you get `E117: Unknown function`, that means there's a runtime
    issue: |faq-runtime|.


:CHECKHEALTH REPORTS E5009: INVALID $VIMRUNTIME ~

This means `health#check()` couldn't load, which suggests that |$VIMRUNTIME|
or 'runtimepath' is broken.

- |$VIMRUNTIME| must point to Nvim's runtime files, not Vim's.
- The |$VIMRUNTIME| directory contents should be readable by the current user.
- Verify that `:echo &runtimepath` contains the $VIMRUNTIME path.
- Check the output of: >vim

    :call health#check()
    :verbose func health#check
<

NEOVIM CAN'T FIND ITS RUNTIME ~

This is the case if `:help nvim` shows `E149: Sorry, no help for nvim`.

Make sure that |$VIM| and |$VIMRUNTIME| point to Nvim's (as opposed to
Vim's) runtime by checking `:echo $VIM` and `:echo $VIMRUNTIME`. This should
give something like `/usr/share/nvim` resp. `/usr/share/nvim/runtime`.

Also make sure that you don't accidentally overwrite your runtimepath
(`:set runtimepath?`), which includes the above |$VIMRUNTIME| by default (see
'runtimepath').


NEOVIM IS SLOW ~


Use a fast terminal emulator:

- kitty https://github.com/kovidgoyal/kitty
- alacritty https://github.com/jwilm/alacritty


Use an optimized build:

`:checkhealth nvim` should report one of these "build types":
>
    Build type: RelWithDebInfo
    Build type: MinSizeRel
    Build type: Release
<
If it reports `Build type: Debug` and you're building Nvim from source, see
https://github.com/neovim/neovim/blob/master/BUILD.md.


COLORS AREN'T DISPLAYED CORRECTLY ~

Ensure that |$TERM| is set correctly.

From a shell, run `TERM=xterm-256color nvim`. If colors are displayed
correctly, then export that value of `TERM` in your user profile (usually
`~/.profile`):
>bash
    export TERM=xterm-256color
<
If you're using `tmux`, instead add this to your `tmux.conf`:
>bash
    set -g default-terminal "tmux-256color"
<

For GNU `screen`, configure your `.screenrc`
<https://wiki.archlinux.org/index.php/GNU_Screen#Use_256_colors>:
>
    term screen-256color
<

NOTE: Nvim ignores `t_Co` and other |t_xx| terminal codes.


NEOVIM CAN'T READ UTF-8 CHARACTERS ~

Run the following from the command line:
>bash
    locale | grep -E '(LANG|LC_CTYPE|LC_ALL)=(.*\.)?(UTF|utf)-?8'
<
If there's no results, then you might not be using a UTF-8 locale. See the
following issues:
#1601 https://github.com/neovim/neovim/issues/1601
#1858 https://github.com/neovim/neovim/issues/1858
#2386 https://github.com/neovim/neovim/issues/2386


ESC IN TMUX OR GNU SCREEN IS DELAYED ~

This is a common problem
https://www.google.com/?q=tmux%20vim%20escape%20delay in `tmux` / `screen`
(see also tmux/#131
https://github.com/tmux/tmux/issues/131#issuecomment-145853211). The
corresponding timeout needs to be tweaked to a low value (10-20ms).

`.tmux.conf`:
>
    set -g escape-time 10
    # Or for tmux >= 2.6
    set -sg escape-time 10
<
`.screenrc`:
>
    maptimeout 10
<

"WHY DOESN'T THIS HAPPEN IN VIM?"

It does happen (try `vim -N -u NONE`), but if you hit a key quickly after
ESC_ then Vim interprets the ESC as ESC instead of ALT (META). You won't
notice the delay unless you closely observe the cursor. The tradeoff is that
Vim won't understand ALT (META) key-chords, so for example `nnoremap <M-a>`
won't work. ALT (META) key-chords always work in Nvim. See also `:help
xterm-cursor-keys` in Vim.

Nvim 0.3 mimics the Vim behavior while still fully supporting ALT mappings. See
|i_ALT|.


ESC IN GNU SCREEN IS LOST WHEN MOUSE MODE IS ENABLED ~

This happens because of a bug in screen https://savannah.gnu.org/bugs/?60196:
in mouse mode, screen assumes that `ESC` is part of a mouse sequence and will
wait an unlimited time for the rest of the sequence, regardless of
`maptimeout`. Until it's fixed in screen, there's no known workaround for
this other than double-pressing escape, which causes a single escape to be
passed through to Nvim.


CALLING INPUTLIST(), ECHOMSG, ... IN FILETYPE PLUGINS AND AUTOCMD DOES NOT WORK ~

#10008 https://github.com/neovim/neovim/issues/10008,
#10116 https://github.com/neovim/neovim/issues/10116,
#12288 https://github.com/neovim/neovim/issues/12288,
# vim/vim#4379 https://github.com/vim/vim/issues/4379.
This is because Nvim sets `shortmess+=F` by default. Vim behaves the same way
with `set shortmes+=F`. There are plans to improve this, but meanwhile as a
workaround, use `set shortmess-=F` or use `unsilent` as follows.
>vim
    unsilent let var = inputlist(['1. item1', '2. item2'])
    autocmd BufNewFile * unsilent echomsg 'The autocmd has been fired.'
<

G:CLIPBOARD SETTINGS ARE NOT USED. ~

If the clipboard provider is already loaded, you will need to reload it after
configuration. Use the following configuration.
>vim
    let g:clipboard = { 'name' : ... }
    if exists('g:loaded_clipboard_provider')
      unlet g:loaded_clipboard_provider
      runtime autoload/provider/clipboard.vim
    endif
<

Or, if you want automatic reloading when assigning to |g:clipboard|, set
|init.vim| as follows.
>vim
    function! s:clipboard_changed(...) abort
      if exists('g:loaded_clipboard_provider')
        unlet g:loaded_clipboard_provider
      endif
      runtime autoload/provider/clipboard.vim
    endfunction

    if !exists('s:loaded")
      call dictwatcheradd(g:, 'clipboard', function('s:clipboard_changed'))
    endif
    let s:loaded = v:true
<

==============================================================================
Build issues                                                    *faq-build*


GENERAL BUILD ISSUES ~

Run `make distclean && make` to rule out a stale build environment causing the
failure.


SETTINGS IN LOCAL.MK DON'T TAKE EFFECT ~

CMake caches build settings, so you might need to run `rm -r build && make`
after modifying `local.mk`.


CMAKE ERRORS ~

`configure_file Problem configuring file`

This is probably a permissions issue, which can happen if you run `make` as the
root user, then later run an unprivileged `make`. To fix this, run `rm -rf
build` and try again.


GENERATING HELPTAGS FAILED ~

If re-installation fails with "Generating helptags failed", try removing the
previously installed runtime directory (if `CMAKE_INSTALL_PREFIX` is not set
during building, the default is `/usr/local/share/nvim`):
>bash
    rm -r /usr/local/share/nvim
<

==============================================================================
Design                                                         *faq-design*


WHY NOT USE JSON FOR RPC? ~

- JSON cannot easily/efficiently handle binary data
- JSON specification is ambiguous: https://seriot.ch/parsing_json.php


WHY EMBED LUA INSTEAD OF X? ~

- Lua is a very small language, ideal for embedding. The biggest advantage of
  Python/Ruby/etc is their huge collection of libraries, but that isn't
  relevant for Nvim, where Nvim is the "batteries included" library:
  introducing another stdlib would be redundant.
- Lua 5.1 is a complete language: the syntax is frozen. This is great for
  backwards compatibility.
- Nvim also uses Lua internally as an alternative to C. Extra performance is
  useful there, as opposed to a slow language like Python or Vim9script.
- LuaJIT is one of the fastest runtimes on the planet, 10x faster than Python
  and "Vim9script" https://vimhelp.org/vim9.txt.html, 100x faster than
  Vimscript.
- Python/JS cost more than Lua in terms of size and portability, and there are
  already numerous Python/JS-based editors. So Python/JS would make Nvim
  bigger and less portable, in exchange for a non-differentiating feature.

See also:

- Why Lua https://web.archive.org/web/20150219224654/https://blog.datamules.com/blog/2012/01/30/why-lua/
- The Design of Lua https://cacm.acm.org/magazines/2018/11/232214-a-look-at-the-design-of-lua/fulltext
- Scripting architecture considerations http://oldblog.antirez.com/post/redis-and-scripting.html
- LuaJIT performance https://julialang.org/benchmarks/
- Discussion of JavaScript vs Lua https://github.com/vim/vim/pull/5198#issuecomment-554693754
- Discussion Python embedding https://lobste.rs/s/pnuak4/mercurial_s_journey_reflections_on#c_zshdwy


WHY LUA 5.1 INSTEAD OF LUA 5.3+? ~

Lua 5.1 is a different language than 5.3. The Lua org makes breaking changes
with every new version, so even if we switched (not upgraded, but switched) to
5.3 we gain nothing when they create the next new language in 5.4, 5.5, etc.
And we would lose LuaJIT, which is far more valuable than Lua 5.3+.

Lua 5.1 is a complete language. To "upgrade" it, add libraries, not syntax.
Nvim itself already is a pretty good "stdlib" for Lua, and we will continue to
grow and enhance it. Changing the rules of Lua gains nothing in this context.


WILL NEOVIM TRANSLATE VIMSCRIPT TO LUA, INSTEAD OF EXECUTING VIMSCRIPT DIRECTLY? ~

- We are experimenting with vim9jit https://github.com/tjdevries/vim9jit to
  transpile Vim9script (Vim9's Vimscript variant) to Lua and have used this to
  port Vim9 plugins https://github.com/neovim/neovim/pull/21662 to Nvim Lua.
- We have no plans for transpiling legacy Vimscript.


ARE PLUGIN AUTHORS ENCOURAGED TO PORT THEIR PLUGINS FROM VIMSCRIPT TO LUA? DO YOU PLAN ON SUPPORTING VIMSCRIPT INDEFINITELY? (#1152) ~

We don't anticipate any reason to deprecate Vimscript, which is a valuable DSL
https://en.wikipedia.org/wiki/Domain-specific_language for text-editing tasks.
Maintaining Vimscript compatibility is less costly than a mass migration of
existing Vim plugins.

Porting from Vimscript to Lua just for the heck of it gains nothing. Nvim is
emphatically a fork of Vim in order to leverage the work already spent on
thousands of Vim plugins, while enabling new types of plugins and
integrations.

vim:tw=78:ts=8:noet:ft=help:norl: