Hi
I’m having this same issue, right after running garbage collect on packages older than 7 days, but I don’t use home-manager. It’s all in my configuration.nix file.
In an attempt to fix it, I commented out all oh-my-posh and fish related lines from configuration.nix, rebuilt, ran garbage-collect again, but without a time limit and then uncommented the same lines, rebuilt (with several restarts in between, although I am including the switch argument when rebuilding), but I’m still getting the same error. Is there a way to force fish to regenerate somehow?
Any help would be appreciated.
The terminal output and the configuration.nix file are below.
Thanks!
edit: I switched to bash in the meantime, to check that the issue isn’t oh-my-posh, and it’s working fine with bash, so it seems the issue was with fish and whatever cached version of oh-my-posh it cannot find.
While writing this edit, I was doing some more testing and in bash I ran exec fish, which started the simple fish shell.
I executed oh-my-posh cache clear.
I then enabled the oh-my-posh promptInit for fish again and executed fish again from inside the bash shell and it ran fine.
So, lastly, I made fish the default shell again and the oh-my-posh integration seems to be working fine.
I can’t say for sure if running the oh-my-posh cache clear did anything or if executing fish from within bash did, but if anyone else encounters this issue, I hope it helps and you don’t end up going as far as garbage-collecting everything in hopes that it helps, like I did 
Terminal
fish: Unknown command: /nix/store/b67118lwnvvc8dsr4w28l5cm9ffx540g-oh-my-posh-26.23.6/bin/oh-my-posh
~/.cache/oh-my-posh/init.14695981039346656037.fish (line 30):
$_omp_executable print $argv[1] \
^~~~~~~~~~~~~~~^
in function '_omp_get_prompt' with arguments 'primary --cleared=false'
called on line 1 of file ~/.cache/oh-my-posh/init.14695981039346656037.fish
in command substitution
called on line 99 of file ~/.cache/oh-my-posh/init.14695981039346656037.fish
in function 'fish_prompt'
in command substitution
fish: Unknown command: /nix/store/b67118lwnvvc8dsr4w28l5cm9ffx540g-oh-my-posh-26.23.6/bin/oh-my-posh
~/.cache/oh-my-posh/init.14695981039346656037.fish (line 30):
$_omp_executable print $argv[1] \
^~~~~~~~~~~~~~~^
in function '_omp_get_prompt' with arguments 'right'
called on line 1 of file ~/.cache/oh-my-posh/init.14695981039346656037.fish
in command substitution
called on line 117 of file ~/.cache/oh-my-posh/init.14695981039346656037.fish
in function 'fish_right_prompt'
in command substitution
configuration.nix file
# Edit this configuration file to define what should be installed on
# your system. Help is available in the configuration.nix(5) man page
# and in the NixOS manual (accessible by running ‘nixos-help’).
{ config, pkgs, ... }:
{
imports =
[ # Include the results of the hardware scan.
./hardware-configuration.nix
];
# Bootloader.
boot.loader.grub.enable = true;
boot.loader.grub.device = "/dev/sda";
boot.loader.grub.useOSProber = true;
# Use latest kernel.
boot.kernelPackages = pkgs.linuxPackages_latest;
# Enable NTFS support at boot
boot.supportedFilesystems = [ "ntfs" ];
fileSystems."/run/media/greyhound/Void" =
{ device = "/dev/disk/by-uuid/000064CF0064CCEA";
fsType = "ntfs-3g";
options = [ "rw" "uid=1000" "nofail" "x-gvfs-show"];
};
networking.hostName = "nixos"; # Define your hostname.
# networking.wireless.enable = true; # Enables wireless support via wpa_supplicant.
# Configure network proxy if necessary
# networking.proxy.default = "http://user:password@proxy:port/";
# networking.proxy.noProxy = "127.0.0.1,localhost,internal.domain";
# Enable networking
networking.networkmanager.enable = true;
# Set your time zone.
time.timeZone = "Europe/Bucharest";
# Select internationalisation properties.
i18n.defaultLocale = "en_US.UTF-8";
i18n.extraLocaleSettings = {
LC_ADDRESS = "en_US.UTF-8";
LC_IDENTIFICATION = "en_US.UTF-8";
LC_MEASUREMENT = "en_US.UTF-8";
LC_MONETARY = "en_US.UTF-8";
LC_NAME = "en_US.UTF-8";
LC_NUMERIC = "en_US.UTF-8";
LC_PAPER = "en_US.UTF-8";
LC_TELEPHONE = "en_US.UTF-8";
LC_TIME = "en_US.UTF-8";
};
security.pam.services.gdm.enableGnomeKeyring = true;
security.pam.services.login.enableGnomeKeyring = true;
services.gnome.gnome-keyring.enable = true;
# Enable the X11 windowing system.
services.xserver.enable = true;
# Enable the GNOME Desktop Environment.
services.displayManager.gdm.enable = true;
services.desktopManager.gnome.enable = true;
# Enable Num Lock at startup
services.displayManager.sddm.autoNumlock = true;
# Configure keymap in X11
services.xserver.xkb = {
layout = "us";
variant = "";
};
# Enable CUPS to print documents.
services.printing.enable = true;
# Enable sound with pipewire.
services.pulseaudio.enable = false;
security.rtkit.enable = true;
services.pipewire = {
enable = true;
alsa.enable = true;
alsa.support32Bit = true;
pulse.enable = true;
# If you want to use JACK applications, uncomment this
#jack.enable = true;
# use the example session manager (no others are packaged yet so this is enabled by default,
# no need to redefine it in your config for now)
#media-session.enable = true;
};
# Enable touchpad support (enabled default in most desktopManager).
# services.xserver.libinput.enable = true;
services.input-remapper = {
enable = true;
};
services.urserver = {
enable = true;
};
# Define a user account. Don't forget to set a password with ‘passwd’.
users.users.greyhound = {
isNormalUser = true;
description = "Greyhound";
extraGroups = [ "networkmanager" "wheel" ];
packages = with pkgs; [
# thunderbird
];
};
users.defaultUserShell = pkgs.fish;
# Enable automatic login for the user.
services.displayManager.autoLogin.enable = true;
services.displayManager.autoLogin.user = "greyhound";
# Workaround for GNOME autologin: https://github.com/NixOS/nixpkgs/issues/103746#issuecomment-945091229
systemd.services."getty@tty1".enable = false;
systemd.services."autovt@tty1".enable = false;
# Install firefox.
programs.firefox = {
package = pkgs.firefox;
enable = true;
nativeMessagingHosts.packages = [ pkgs.firefoxpwa ];
};
#install Steam
programs.steam = {
enable = true;
remotePlay.openFirewall = true; # Open ports in the firewall for Steam Remote Play
dedicatedServer.openFirewall = true; # Open ports in the firewall for Source Dedicated Server
localNetworkGameTransfers.openFirewall = true; # Open ports in the firewall for Steam Local Network Game Transfers
};
programs.nh = {
enable = true;
};
fonts.fontconfig = {
enable = true;
# defaultFonts.emoji = [ "Noto Color Emoji" ];
defaultFonts.emoji = [ "Apple Color Emoji" ];
};
# Allow unfree packages
nixpkgs.config.allowUnfree = true;
nix.settings.experimental-features = [ "nix-command" ];
nix.settings.download-buffer-size = 671088640;
# List packages installed in system profile. To search, run:
# $ nix search wget
environment.systemPackages = with pkgs; [
# vim # Do not forget to add an editor to edit configuration.nix! The Nano editor is also installed by default.
# wget
firefoxpwa
vim
neovim
alacritty
vlc
mpv
wget
git
vscode
qbittorrent
beeper
wine
# albert
# valent
# rustdesk
# spacedrive
rustup
# python3Full
discord
emacs
libreoffice-qt6-fresh
hunspell
hunspellDicts.en_US
hunspellDicts.ro_RO
emote
smplayer
distrobox
# helix
# kitty
# foot
# ghostty
# guake
# tabby
# terminator
# tilda
# warp
# warp-terminal
# waveterm
# zed-editor
neofetch
fastfetch
nil
nixd
# notion-app-enhanced
# obsidian
nerdfetch
oh-my-posh
nerd-fonts.symbols-only
nerd-fonts.hack
# noto-fonts-color-emoji
vscodium
junction
browsers
# stremio
noip
file
# sublime4
# urserver
# ulauncher
### Gnome
gnome-menus
gnome-tweaks
gnome-browser-connector
gnomeExtensions.gsconnect
gnomeExtensions.arcmenu
gnomeExtensions.just-perfection
gnomeExtensions.freon
gnomeExtensions.bing-wallpaper-changer
gnomeExtensions.dash-to-panel
gnomeExtensions.tray-icons-reloaded
# nautilus-python
];
# Some programs need SUID wrappers, can be configured further or are
# started in user sessions.
# programs.mtr.enable = true;
# programs.gnupg.agent = {
# enable = true;
# enableSSHSupport = true;
# };
programs.fish = {
enable = true;
promptInit = "oh-my-posh init fish | source";
};
programs.xfconf = {
enable = true;
};
# Enable AppImage support
programs.appimage = {
enable = true; # Enable AppImage integration
binfmt = true; # Enable AppImage binary format support
};
programs.direnv = {
enable = true;
enableFishIntegration = true;
};
virtualisation.podman = {
enable = true;
dockerCompat = true;
};
# List services that you want to enable:
# Enable the OpenSSH daemon.
# services.openssh.enable = true;
# Open ports in the firewall.
# networking.firewall.allowedTCPPorts = [ ... ];
# networking.firewall.allowedUDPPorts = [ ... ];
networking.firewall = rec {
allowedTCPPortRanges = [ { from = 1714; to = 1764; } { from = 9510; to = 9512; } { from = 11470; to = 11470; } { from = 12470; to = 12470; } { from = 56852; to = 56852;} ];
allowedUDPPortRanges = allowedTCPPortRanges;
};
# Or disable the firewall altogether.
# networking.firewall.enable = false;
# Disable suspend of Toslink output to prevent audio popping.
services.pipewire.wireplumber.extraConfig."99-disable-suspend" = {
"monitor.alsa.rules" = [
{
matches = [
{
"node.name" = "alsa_output.pci-0000_00_1b.0.analog-stereo";
}
];
actions = {
update-props = {
"session.suspend-timeout-seconds" = 0;
};
};
}
];
};
services.flatpak.enable = true;
services.gvfs.enable = true; # Mount, trash, and other functionalities
services.tumbler.enable = true; # Thumbnail support for images
services.gnome.sushi.enable = true;
xdg.mime.defaultApplications = {
"application/x-bittorrent" = "qbittorrent.desktop";
};
system.autoUpgrade.enable = true;
system.autoUpgrade.allowReboot = true;
system.autoUpgrade.channel = "https://channels.nixos.org/nixos-unstable";
# This value determines the NixOS release from which the default
# settings for stateful data, like file locations and database versions
# on your system were taken. It‘s perfectly fine and recommended to leave
# this value at the release version of the first install of this system.
# Before changing this value read the documentation for this option
# (e.g. man configuration.nix or on https://nixos.org/nixos/options.html).
system.stateVersion = "25.05"; # Did you read the comment?
}