No code fix available in F# (generate DU stubs, implement abstract members...)

[nkosi23]

Hello,

I see no code fixes available in my F# files, for example when it comes to generating stubs for union cases in pattern matching expressions, or implementing the abstract members of a class. I correctly see the warnings underlined in yellow (for pattern matching expressions), and compiler errors (for abstract members not defined), but no Quick Fix action is available in vscode.

However I do get code fixes to generate XML comment on top of a file. I have been able to pinpoint the problem down to the fact that any quick action involving generating code is apparently absent. I do have intellisense available, even though it appears with a large lag (i first see only dictionnary words suggestions, and then after typing a few more letters, i see proper intellisense).

I have confirmed that this issue is specific to Ionide, as I have code fixes available in my C# projects located in the same solution. Moreover, the same works properly in JetBrains Rider. I have tripled check the relevant settings, and just spent 3 hours investigating this with the help of LLMs without success. I have even tried to reinstall the extension but it didn't help unfortunately.

[nkosi23]

Here is my environment:

Vs Code:

Version: 1.100.0
Commit: 19e0f9e681ecb8e5c09d8784acaa601316ca4571
Date: 2025-05-07T12:48:53.763Z
Electron: 34.5.1
ElectronBuildId: 11369351
Chromium: 132.0.6834.210
Node.js: 20.19.0
V8: 13.2.152.41-electron.0
OS: Linux x64 6.14.4-1-default

Ionide 7.26.2

And the output from Ionide:

[16:07:11 DEBUG] [Main] Activating features
[16:08:00 DEBUG] [Main] Restarting F# language service
[16:08:00 DEBUG] [LanguageService] FSAC (NETCORE): '/home/somedev/.vscode/extensions/ionide.ionide-fsharp-7.26.2/bin/net9.0/fsautocomplete.dll'
[16:08:00 DEBUG] [LanguageService] F# language server options: % {
  command: '/usr/bin/dotnet',
  args: [
    '/home/somedev/.vscode/extensions/ionide.ionide-fsharp-7.26.2/bin/net9.0/fsautocomplete.dll',
    '--state-directory',
    '/home/somedev/.config/Code/User/workspaceStorage/d39044573ecc8790f690f90f9c9ddad0/Ionide.Ionide-fsharp'
  ],
  options: {
    env: {
      AUDIODRIVER: 'pulseaudio',
      CHROME_DESKTOP: 'code.desktop',
      CONFIG_SITE: '/usr/share/site/x86_64-pc-linux-gnu',
      CPU: 'x86_64',
      CSHEDIT: 'emacs',
      DBUS_SESSION_BUS_ADDRESS: 'unix:path=/run/user/1000/bus',
      DEBUGINFOD_URLS: 'https://debuginfod.opensuse.org/ ',
      DESKTOP_SESSION: 'default',
      DISPLAY: ':0',
      GDK_BACKEND: 'x11',
      GPG_TTY: 'pas un tty',
      GTK2_RC_FILES: '/etc/gtk-2.0/gtkrc:/home/somedev/.gtkrc-2.0:/home/somedev/.config/gtkrc-2.0',
      GTK_IM_MODULE: 'ibus',
      GTK_MODULES: 'canberra-gtk-module',
      GTK_RC_FILES: '/etc/gtk/gtkrc:/home/somedev/.gtkrc:/home/somedev/.config/gtkrc',
      G_BROKEN_FILENAMES: '1',
      G_FILENAME_ENCODING: '@locale,UTF-8,ISO-8859-15,CP1252',
      HISTSIZE: '1000',
      HOME: '/home/somedev',
      HOST: 'localhost.localdomain',
      HOSTNAME: 'localhost.localdomain',
      HOSTTYPE: 'x86_64',
      ICEAUTHORITY: '/run/user/1000/iceauth_oZpaxn',
      INPUT_METHOD: 'ibus',
      INVOCATION_ID: '6dd378831a7644c7bc9b397452ebb022',
      JOURNAL_STREAM: '9:19600',
      JRE_HOME: '/usr/lib64/jvm/java-11-openjdk-11',
      KDE_APPLICATIONS_AS_SCOPE: '1',
      KDE_FULL_SESSION: 'true',
      KDE_SESSION_UID: '1000',
      KDE_SESSION_VERSION: '6',
      LANG: 'fr_FR.UTF-8',
      LESS: '-M -I -R',
      LESSCLOSE: 'lessclose.sh %s %s',
      LESSKEY: '/usr/etc/lesskey.bin',
      LESSOPEN: 'lessopen.sh %s',
      LESS_ADVANCED_PREPROCESSOR: 'no',
      LOGNAME: 'somedev',
      LS_COLORS: 'no=00:fi=00:di=01;34:ln=01;36:pi=40;33:so=01;35:do=01;35:bd=40;33;01:cd=40;33;01:or=40;31;01:mi=00:su=37;41:sg=30;43:ca=00:tw=30;42:ow=34;42:st=37;44:ex=01;32:*.7z=01;31:*.ace=01;31:*.alz=01;31:*.apk=01;31:*.arc=01;31:*.arj=01;31:*.bz=01;31:*.bz2=01;31:*.cab=01;31:*.cpio=01;31:*.crate=01;31:*.deb=01;31:*.drpm=01;31:*.dwm=01;31:*.dz=01;31:*.ear=01;31:*.egg=01;31:*.esd=01;31:*.gz=01;31:*.jar=01;31:*.lha=01;31:*.lrz=01;31:*.lz=01;31:*.lz4=01;31:*.lzh=01;31:*.lzma=01;31:*.lzo=01;31:*.pyz=01;31:*.rar=01;31:*.rpm=01;31:*.rz=01;31:*.sar=01;31:*.swm=01;31:*.t7z=01;31:*.tar=01;31:*.taz=01;31:*.tbz=01;31:*.tbz2=01;31:*.tgz=01;31:*.tlz=01;31:*.txz=01;31:*.tz=01;31:*.tzo=01;31:*.tzst=01;31:*.udeb=01;31:*.war=01;31:*.whl=01;31:*.wim=01;31:*.xz=01;31:*.z=01;31:*.Z=01;31:*.zip=01;31:*.zoo=01;31:*.zst=01;31:*.asf=01;35:*.avi=01;35:*.avif=01;35:*.bmp=01;35:*.cgm=01;35:*.dl=01;35:*.emf=01;35:*.flc=01;35:*.fli=01;35:*.flv=01;35:*.gif=01;35:*.gl=01;35:*.jpeg=01;35:*.jpg=01;35:*.m2v=01;35:*.m4v=01;35:*.mjpeg=01;35:*.mjpg=01;35:*.mkv=01;35:*.mng=01;35:*.mov=01;35:*.mp4=01;35:*.mp4v=01;35:*.mpeg=01;35:*.mpg=01;35:*.nuv=01;35:*.ogm=01;35:*.pbm=01;35:*.pcx=01;35:*.pgm=01;35:*.png=01;35:*.ppm=01;35:*.qt=01;35:*.rm=01;35:*.rmvb=01;35:*.svg=01;35:*.svgz=01;35:*.tga=01;35:*.tif=01;35:*.tiff=01;35:*.vob=01;35:*.webm=01;35:*.webp=01;35:*.wmv=01;35:*.xbm=01;35:*.xcf=01;35:*.xpm=01;35:*.xwd=01;35:*.yuv=01;35:*.ogv=01;35:*.ogx=01;35:*.aac=00;36:*.aiff=00;36:*.ape=00;36:*.au=00;36:*.flac=00;36:*.m4a=00;36:*.mid=00;36:*.midi=00;36:*.mka=00;36:*.mp3=00;36:*.mpc=00;36:*.ogg=00;36:*.ra=00;36:*.voc=00;36:*.wav=00;36:*.wma=00;36:*.wv=00;36:*.oga=00;36:*.opus=00;36:*.spx=00;36:*.xspf=00;36:*#=00;90:*~=00;90:*.bak=00;90:*.crdownload=00;90:*.dpkg-dist=00;90:*.dpkg-new=00;90:*.dpkg-old=00;90:*.dpkg-tmp=00;90:*.old=00;90:*.orig=00;90:*.part=00;90:*.rej=00;90:*.rpmnew=00;90:*.rpmorig=00;90:*.rpmsave=00;90:*.swp=00;90:*.tmp=00;90:*.ucf-dist=00;90:*.ucf-new=00;90:*.ucf-old=00;90:',
      LS_OPTIONS: '-N --color=tty -T 0',
      MACHTYPE: 'x86_64-suse-linux',
      MAIL: '/var/mail/somedev',
      MANAGERPID: '1803',
      MANPATH: '/usr/local/man:/usr/share/man',
      MANPATHISSET: 'yes',
      MINICOM: '-c on',
      MORE: '-sl',
      MOZ_GMP_PATH: '/usr/lib64/mozilla/plugins/gmp-gmpopenh264/system-installed',
      NO_AT_BRIDGE: '1',
      ORIGINAL_XDG_CURRENT_DESKTOP: 'KDE',
      OSTYPE: 'linux',
      PAGER: 'less',
      PATH: '/home/somedev/.local/bin:/home/somedev/bin:/usr/local/bin:/usr/bin:/bin:/home/somedev/.dotnet/tools',
      PROFILEREAD: 'true',
      PWD: '/home/somedev',
      PYTHONSTARTUP: '/etc/pythonstart',
      QEMU_AUDIO_DRV: 'pa',
      QT4_IM_MODULE: 'xim',
      QT_AUTO_SCREEN_SCALE_FACTOR: '0',
      QT_IM_MODULE: 'ibus',
      QT_IM_SWITCHER: 'imsw-multi',
      QT_WAYLAND_RECONNECT: '1',
      SESSION_MANAGER: 'local/localhost.localdomain:@/tmp/.ICE-unix/1968,unix/localhost.localdomain:/tmp/.ICE-unix/1968',
      SHELL: '/bin/bash',
      SHLVL: '0',
      SSH_AGENT_PID: '1901',
      SSH_ASKPASS: '/usr/libexec/ssh/ssh-askpass',
      SSH_AUTH_SOCK: '/tmp/ssh-XXXXXXprtETa/agent.1815',
      SYSTEMD_EXEC_PID: '2071',
      TERM: 'xterm',
      USER: 'somedev',
      VENDOR: 'suse',
      VSCODE_CODE_CACHE_PATH: '/home/somedev/.config/Code/CachedData/19e0f9e681ecb8e5c09d8784acaa601316ca4571',
      VSCODE_CRASH_REPORTER_PROCESS_TYPE: 'extensionHost',
      VSCODE_CWD: '/home/somedev',
      VSCODE_ESM_ENTRYPOINT: 'vs/workbench/api/node/extensionHostProcess',
      VSCODE_HANDLES_UNCAUGHT_ERRORS: 'true',
      VSCODE_IPC_HOOK: '/run/user/1000/vscode-627fa58c-1.10-main.sock',
      VSCODE_NLS_CONFIG: '{"userLocale":"en-us","osLocale":"fr-fr","resolvedLanguage":"en","defaultMessagesFile":"/usr/share/code/resources/app/out/nls.messages.json","locale":"en-us","availableLanguages":{}}',
      VSCODE_PID: '2165842',
      WINDOWMANAGER: '/usr/bin/startplasma-x11',
      XAUTHLOCALHOSTNAME: 'localhost.localdomain',
      XAUTHORITY: '/tmp/xauth_Tebzea',
      XDG_CONFIG_DIRS: '/home/somedev/.config/kdedefaults:/etc/xdg:/usr/local/etc/xdg:/usr/etc/xdg',
      XDG_CURRENT_DESKTOP: 'KDE',
      XDG_DATA_DIRS: '/home/somedev/.local/share/flatpak/exports/share:/var/lib/flatpak/exports/share:/usr/local/share:/usr/share',
      XDG_MENU_PREFIX: 'plasma-',
      XDG_RUNTIME_DIR: '/run/user/1000',
      XDG_SEAT: 'seat0',
      XDG_SEAT_PATH: '/org/freedesktop/DisplayManager/Seat0',
      XDG_SESSION_CLASS: 'user',
      XDG_SESSION_DESKTOP: 'KDE',
      XDG_SESSION_ID: '1',
      XDG_SESSION_PATH: '/org/freedesktop/DisplayManager/Session0',
      XDG_SESSION_TYPE: 'x11',
      XDG_VTNR: '2',
      XKEYSYMDB: '/usr/X11R6/lib/X11/XKeysymDB',
      XMODIFIERS: '@im=ibus',
      XNLSPATH: '/usr/share/X11/nls',
      XSESSION_IS_UP: 'yes',
      ZYPP_PCK_PRELOAD: '1',
      _: '/usr/share/code/code',
      marten_testing_database: 'Host=localhost;Port=5432;Database=marten_testing;Username=marten_test;password=marten_test_pass;Command Timeout=5',
      ELECTRON_RUN_AS_NODE: '1',
      VSCODE_L10N_BUNDLE_LOCATION: '',
      VSCODE_DOTNET_INSTALL_TOOL_ORIGINAL_HOME: '/home/somedev',
      DOTNET_MULTILEVEL_LOOKUP: 'undefined',
      DOTNET_CLI_UI_LANGUAGE: 'en-US',
      DOTNET_NOLOGO: 'true',
      DOTNET_GCNoAffinitize: 0,
      DOTNET_GCHeapCount: '0',
      DOTNET_GCConserveMemory: 0,
      DOTNET_GCServer: 1
    }
  }
}

[MangelMaxime]

To confirm that this is not working even for a simple case can you please try this:

1. Create a new fsx file
2. Put this content:

type Test =
    | User 
    | Name

match user with
| User -> ()

3. Try to move your mouse to user and see if you get Code fixes suggestions

Kooha-2025-06-17-09-03-08.webm

Moreover, the same works properly in JetBrains Rider.

The code fixes is provided by different layers for VSCode and JetBrains Rider, which can explains why it works for one of the tool but not the other.

[nkosi23]

Thanks a lot for your help, i do get the code fixes suggestions in the minimal repro!
Intellisense is also much faster/snappier than in the rest of the solution.

Actually, after testing this further i have just noticed that everything works like charm everywhere now (and intellisense is snappy everywhere). The only change I have done is rebooting my computer lol...

Well, I also removed a bunch of obsolete projects from the solution, and sanitized the .sln solution using an LLM because apparently my manual changes to the solution file made it invalid and prevented Ionide from loading the solution. I made these changes after posting this message, initially the solution was loading without problem. But i am now thinking that maybe, there were actually latent issues with this file which caused Ionide to malfunction. Because if I remember correctly, after corrupting the file (by leaving around metadata references to projects no longer present in the solution), Ionide was no longer available solution wide, but it did function partially (but with even more missing items than before this problem).

This would deserve further investigation, but unfortunately i do not have time to do it, so i'll just close and leave this discussion here in case it can give pointers to someone facing the same problem in the future.

Not clear at all what happened but at least everything seems to work now. Thank you again for your help