Error with tagbar addon: E716: Key not present in Dictionary: n

[reinerh]

When using rust.vim with tagbar, vim throws an error in Rust files that contain a module when opening the tagbar.
(When using also the airline addon, it shows the error immediately on start, as airline is also using tag data for the status line.)
Without rust.vim (i.e., only with the tagbar addon active), the tagbar is shown correctly and without any errors (that's why I'm filing this bug here and not for tagbar).

• rust.vim version: fdb2d39 (Feb 18 2019)

Steps to reproduce:

Create a new library cargo project.

$ cargo new --lib hello

Open src/lib.rs with vim and open tagbar with :Tagbar.

Expected behavior:

vim displays the tagbar with tags of the current .rs file.

Actual behavior:

vim throws this error:

Error detected while processing function tagbar#ToggleWindow[2]..<SNR>37_ToggleWindow[9]..<SNR>37_OpenWindow[83]..<SNR>37_AutoUpdate[63]..<SNR>37_ProcessFile[84]..<SNR>37_ParseTagline[76]..<SNR>37_ProcessTag[74]..<SNR>37_add_tag_recursive[
96]..<SNR>37_create_pseudotag[32]..<SNR>43_initFoldState:
line   13:
E716: Key not present in Dictionary: n

RustInfo:

rust.vim Global Variables:

let g:ftplugin_rust_source_path = v:null
let g:loaded_syntastic_rust_cargo_checker = v:null
let g:loaded_syntastic_rust_filetype = v:null
let g:loaded_syntastic_rust_rustc_checker = v:null
let g:rust_bang_comment_leader = v:null
let g:rust_cargo_avoid_whole_workspace = v:null
let g:rust_clip_command = v:null
let g:rust_conceal = v:null
let g:rust_conceal_mod_path = v:null
let g:rust_conceal_pub = v:null
let g:rust_fold = v:null
let g:rust_last_args = v:null
let g:rust_last_rustc_args = v:null
let g:rust_original_delimitMate_excluded_regions = v:null
let g:rust_playpen_url = v:null
let g:rust_prev_delimitMate_quotes = v:null
let g:rust_recent_nearest_cargo_tol = v:null
let g:rust_recent_root_cargo_toml = v:null
let g:rust_recommended_style = v:null
let g:rust_set_conceallevel = v:null
let g:rust_set_conceallevel=1 = v:null
let g:rust_set_foldmethod = v:null
let g:rust_set_foldmethod=1 = v:null
let g:rust_shortener_url = v:null
let g:rustc_makeprg_no_percent = v:null
let g:rustc_path = v:null
let g:rustfmt_autosave = 0
let g:rustfmt_autosave_because_of_config = v:null
let g:rustfmt_autosave_if_config_present = v:null
let g:rustfmt_command = 'rustfmt'
let g:rustfmt_emit_files = 1
let g:rustfmt_fail_silently = 0
let g:rustfmt_options = ''
let g:syntastic_extra_filetypes = ['rust']
let g:syntastic_rust_cargo_fname = v:null
rustfmt 1.0.1-stable (be13559 2018-12-10)

rustc 1.32.0

cargo 1.32.0


VIM - Vi IMproved 8.1 (2018 May 18, compiled Feb 22 2019 12:55:04)
Included patches: 1-875, 878, 884, 948
Modified by team+vim@tracker.debian.org
Compiled by team+vim@tracker.debian.org
Huge version with GTK3 GUI.  Features included (+) or not (-):
+acl               +cindent           +cursorshape       +file_in_path      +jumplist          +mksession         +mouse_xterm       +printer           +startuptime       +termresponse      +visualextra       +xsmp_interact
+arabic            +clientserver      +dialog_con_gui    +find_in_path      +keymap            +modify_fname      +multi_byte        +profile           +statusline        +textobjects       +viminfo           +xterm_clipboard
+autocmd           +clipboard         +diff              +float             +lambda            +mouse             +multi_lang        -python            -sun_workshop      +textprop          +vreplace          -xterm_save
+autochdir         +cmdline_compl     +digraphs          +folding           +langmap           +mouseshape        -mzscheme          +python3           +syntax            +timers            +wildignore        
-autoservername    +cmdline_hist      +dnd               -footer            +libcall           +mouse_dec         +netbeans_intg     +quickfix          +tag_binary        +title             +wildmenu          
+balloon_eval      +cmdline_info      -ebcdic            +fork()            +linebreak         +mouse_gpm         +num64             +reltime           +tag_old_static    +toolbar           +windows           
+balloon_eval_term +comments          +emacs_tags        +gettext           +lispindent        -mouse_jsbterm     +packages          +rightleft         -tag_any_white     +user_commands     +writebackup       
+browse            +conceal           +eval              -hangul_input      +listcmds          +mouse_netterm     +path_extra        +ruby              +tcl               +vartabs           +X11               
++builtin_terms    +cryptv            +ex_extra          +iconv             +localmap          +mouse_sgr         +perl              +scrollbind        +termguicolors     +vertsplit         -xfontset          
+byte_offset       +cscope            +extra_search      +insert_expand     +lua               -mouse_sysmouse    +persistent_undo   +signs             +terminal          +virtualedit       +xim               
+channel           +cursorbind        +farsi             +job               +menu              +mouse_urxvt       +postscript        +smartindent       +terminfo          +visual            +xpm               
   system vimrc file: "$VIM/vimrc"
     user vimrc file: "$HOME/.vimrc"
 2nd user vimrc file: "~/.vim/vimrc"
      user exrc file: "$HOME/.exrc"
  system gvimrc file: "$VIM/gvimrc"
    user gvimrc file: "$HOME/.gvimrc"
2nd user gvimrc file: "~/.vim/gvimrc"
       defaults file: "$VIMRUNTIME/defaults.vim"
    system menu file: "$VIMRUNTIME/menu.vim"
  fall-back for $VIM: "/usr/share/vim"
Compilation: gcc -c -I. -Iproto -DHAVE_CONFIG_H -DFEAT_GUI_GTK  -pthread -I/usr/include/gtk-3.0 -I/usr/include/at-spi2-atk/2.0 -I/usr/include/at-spi-2.0 -I/usr/include/dbus-1.0 -I/usr/lib/x86_64-linux-gnu/dbus-1.0/include -I/usr/include/gtk-3.0 -I/usr/include/gio-unix-2.0 -I/usr/include/cairo -I/usr/include/libdrm -I/usr/include/pango-1.0 -I/usr/include/harfbuzz -I/usr/include/pango-1.0 -I/usr/include/fribidi -I/usr/include/atk-1.0 -I/usr/include/cairo -I/usr/include/pixman-1 -I/usr/include/freetype2 -I/usr/include/libpng16 -I/usr/include/gdk-pixbuf-2.0 -I/usr/include/libmount -I/usr/include/blkid -I/usr/include/uuid -I/usr/include/glib-2.0 -I/usr/lib/x86_64-linux-gnu/glib-2.0/include -Wdate-time  -g -O2 -fdebug-prefix-map=/build/vim-nWVbVg/vim-8.1.0875=. -fstack-protector-strong -Wformat -Werror=format-security -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=1       
Linking: gcc   -L. -Wl,-z,relro -Wl,-z,now -fstack-protector -rdynamic -Wl,-export-dynamic -Wl,-E  -Wl,-z,relro -Wl,-z,now -Wl,--as-needed -o vim   -lgtk-3 -lgdk-3 -lpangocairo-1.0 -lpango-1.0 -latk-1.0 -lcairo-gobject -lcairo -lgdk_pixbuf-2.0 -lgio-2.0 -lgobject-2.0 -lglib-2.0 -lSM -lICE -lXpm -lXt -lX11 -lXdmcp -lSM -lICE  -lm -ltinfo -lnsl  -lselinux  -lacl -lattr -lgpm -ldl  -L/usr/lib -llua5.2 -Wl,-E  -fstack-protector-strong -L/usr/local/lib  -L/usr/lib/x86_64-linux-gnu/perl/5.28/CORE -lperl -ldl -lm -lpthread -lcrypt  -L/usr/lib/python3.7/config-3.7m-x86_64-linux-gnu -lpython3.7m -lcrypt -lpthread -ldl -lutil -lm -L/usr/lib/x86_64-linux-gnu -ltcl8.6 -ldl -lz -lpthread -lm -lruby-2.5 -lpthread -lgmp -ldl -lcrypt -lm     

[oHaiyang]

Same problem here. Are you using universal-ctags?

[reinerh]

Yes, I am.

[oHaiyang]

I dug on this problem for hours, found its caused by tags generated by universal-ctags are not recognized by tagbar, also not by tagbar configs in rust-vim.

try to add these lines into your vimrc:

let g:rust_use_custom_ctags_defs = 1  "ignore https://github.com/rust-lang/rust.vim/blob/master/ctags/rust.ctags 
if !exists('g:tagbar_type_rust')
   let g:tagbar_type_rust = {
       \ 'ctagstype' : 'rust',
       \ 'kinds' : [ "https://github.com/universal-ctags/ctags/blob/master/parsers/rust.c#L50-L61
         \'M:macro,Macro Definition',
         \'P:method,A method',
         \'c:implementation,implementation',
         \'e:enumerator,An enum variant',
         \'f:function,Function',
         \'g:enum,Enum',
         \'i:interface,trait interface',
         \'m:field,A struct field',
         \'n:module,module',
         \'s:struct,structural type',
         \'t:typedef,Type Alias',
         \'v:variable,Global variable',
       \ ]
   \ }
endif

[reinerh]

@oHaiyang Adding your snippet to my .vimrc solved the errors for me.
Thanks a lot!

Btw. tagbar without rust.vim was already showing some tags, so I wouldn't say that they are "not recognized". But with your fix and rust.vim it shows more fields.

[ngortheone]

@oHaiyang
Thanks for the fix!

It looks like neovim has this plugin 'in the box', but a bit outdated as RustFmt was not working (#192) for me.

So I installed this plugin explicitly and RustFmt started to work. But then I got this issue.
I can confirm that the fix is working, the only small thing is that there is missing ", at the end of \ 'kinds' line.

Separate question:
How (often) do changes from this repo get pulled into neovim?

[da-x]

Made some changes now, that if you're using Universal Ctags, it should just work out of the box.

[smheidrich]

I'm still getting this same error because my distribution ships universal-ctags's executable as ctags-universal (not just ctags), so the current check for universal-ctags is not enough.

To make Tagbar use ctags-universal and not regular ctags in the first place, I have to do let g:tagbar_ctags_bin = 'ctags-universal' - so perhaps the contents of this option should be checked first, before falling back to ctags.

I might write a PR to this effect.

[reinerh]

@smheidrich universal-ctags is registered as an "alternative" for ctags. /usr/bin/ctags is a symlink to one of the installed ctags implementations. So you probably have more than one ctags installed.
You can also manually update the alternative with "update-alternatives" (or keep only universal-ctags installed).

[smheidrich]

@reinerh Yep I know (wrote this as a footnote under my comment originally but decided it would only make things more confusing to read), but that doesn't change the justification for the PR - just the facts that Tagbar allows you to change the executable and rust.vim completely ignores it are enough. Thanks anyway!