tl;dr
When a command is not found, the new built-in command fish_command_not_found query package manager every time. It's a kind of nice but I don't need it. To prevent this, I created empty function file ~/.config/fish/functions/fish_command_not_found.fish.
All you need to know is written in here:
fish_command_not_found - what to do when a command wasn't found — fish-shell 3.2.1 documentation
Log
Done with the following environment.
$ uname -srmo
Linux 5.11.9-arch1-1 x86_64 GNU/Linux
$ fish --version
fish, version 3.2.1
Background
When a command is not found, below warnings are now displayed.
$ FBReader
fish: Unknown command: FBReader
warning: database file for 'core' does not exist (use '-Fy' to download)
warning: database file for 'extra' does not exist (use '-Fy' to download)
warning: database file for 'community' does not exist (use '-Fy' to download)
warning: database file for 'multilib' does not exist (use '-Fy' to download)
By executing # pacman -Fy as written, these warnings disappear and message will look like this:
$ FBReader
fish: Unknown command: FBReader
usr/bin/FBReader is owned by community/fbreader 0.99.4-9
Initially, I was satisfied with this, but then I wondered who was printing and querying. I looked it up and found it all in the official documentation.
When fish tries to execute a command and can't find it, it invokes this function.
It can print a message to tell you about it, and it often also checks for a missing package that would include the command.
...
This command was introduced in fish 3.2.0. Previous versions of fish used the "fish_command_not_found" event instead.
fish_command_not_found - what to do when a command wasn't found — fish-shell 3.2.1 documentation
In my system, fish_command_not_found is defined as below:
$ type fish_command_not_found
fish_command_not_found is a function with definition
# Defined in /usr/share/fish/functions/fish_command_not_found.fish @ line 61
function fish_command_not_found
set -l paths $argv[1]
# If we've not been given an absolute path, try $PATH as the starting point,
# otherwise pacman will try *every path*, and e.g. bash-completion
# isn't helpful.
string match -q '/*' -- $argv[1]; or set paths $PATH/$argv[1]
# Pacman only prints the path, so we still need to print the error.
__fish_default_command_not_found_handler $argv[1]
pacman -F $paths
end
Disabling
Querying package manager is nice user friendly feature, but I don't need it. The delay due to querying is more disturbing to me.
According to the document:
When you leave fish_command_not_found undefined (e.g. by adding an empty function file) or explicitly call __fish_default_command_not_found_handler, fish will just print a simple error.
fish_command_not_found - what to do when a command wasn't found — fish-shell 3.2.1 documentation
$ touch ~/.config/fish/functions/fish_command_not_found.fish
$ FBReader
fish: Unknown command: FBReader
🎉