pacman command-not-found handler too slow

[Joe23232]

If I put in some incorrect command that does not exist, for some weird reason it takes a long time before it again shows the prompt.

Here is what I mean.

I have tried running these commands (after logging in back to bash) after cding into the directory of the config files of fish.

rm -fr fish

I tried to uninstall fish:

sudo pacman -Rcs fish

ANd then I did reinstall it:

sudo pacman -S fish

I did a reboot and still the same issues. Any idea?

[faho]

So we have this issue template, it would be nice if you filled it out.

In particular your fish version is of interest here. Is this fish 3.2.0 or fish 3.1.2?

Do you have any customization? Can you confirm that you did indeed remove ~/.config/fish? The way you phrased it makes it sound like you deleted ~/.config/fish/fish, which won't help.

Then there's the simple question: What changed about your system recently? Did you update anything, change any configuration?

This now sounds like it's just nonexistent commands. In that case fish executes the fish_command_not_found function, which will try to ask pacman, which will take a while.

What happens if you replace that handler with the one that just prints the error:

function fish_command_not_found
    __fish_default_command_not_found_handler $argv
end

[faho]

Yeah, arch just updated to 3.2.0, and that adds a command-not-found handler based on pacman's file database.

Unfortunately that's kinda slow, but there's nothing we can do about that. You can disable it by doing as I said above, or you can install pkgfile which is faster.

[IlanCosman]

Honestly I'd say the feature isn't worth the cost right now. It's remarkably annoying because you just mispelled something (already a small annoyance), and instead of immediately correcting it you have to wait for a second like the machine is laughing at you. 😄

Could we perhaps cache the pacman file database on startup or something?

[faho]

Could we perhaps cache the pacman file database on startup or something?

Nope, it's not caching, subsequent calls aren't really faster.

This just takes a bit, depending on the machine. On my laptop it's ~1.5s, which seems okay since trying to execute an unavailable command shouldn't happen too often - it's already highlighted as invalid!

[Joe23232]

Yeah, arch just updated to 3.2.0, and that adds a command-not-found handler based on pacman's file database.

How come it uses pacman, I don't quite get that if I am not using pacman, just fish to type in an incorrect command?

You can disable it by doing as I said above

function fish_command_not_found
    __fish_default_command_not_found_handler $argv
end

Do I just add this to the config file?

[IlanCosman]

How come it uses pacman, I don't quite get that if I am not using pacman, just fish to type in an incorrect command?

When Fish can't find the command you entered, it asks your package manager, in this case pacman, to look for relevant packages to install. If pacman is slow, then that process might take a bit.

Do I just add this to the config file?

Yes, you add it to config.fish

[zanchey]

That's obnoxiously slow in my view; could we suggest that the Arch maintainers disable this by default? It's pretty reminiscent of the sl utility, which was supposed to train people to type ls correctly but in fact just caused rage.

[Joe23232]

When Fish can't find the command you entered, it asks your package manager, in this case pacman, to look for relevant packages to install. If pacman is slow, then that process might take a bit.

Oh that makes perfect sense and that could be a nice handy feature actually.

Yes, you add it to config.fish

Thanks mate :)

Unfortunately that's kinda slow, but there's nothing we can do about that. You can disable it by doing as I said above, or you can install pkgfile which is faster.

You mentioned I can also use pkgfile. So is this built on top of pacman?

[Joe23232]

@IlanCosman

Hi mate, I don't think I am supposed to add:

function fish_command_not_found
    __fish_default_command_not_found_handler $argv
end

to the config file.

What am I supposed to do for it to stop searching through pacman?

[IlanCosman]

What am I supposed to do for it to stop searching through pacman?

You... add that snippet to your config.fish. Or, to make it easier, you can just paste the snippet into the commandline, run it, and then run funcsave fish_command_not_found.

[Joe23232]

What am I supposed to do for it to stop searching through pacman?

You... add that snippet to your config.fish. Or, to make it easier, you can just paste the snippet into the commandline, run it, and then run funcsave fish_command_not_found.

That seems to have worked, thanks :) But how does it work? This entire command?

[IlanCosman]

The snippet simply makes the fish_command_not_found function pass its arguments through to fast default command_not_found handler. When you paste the snippet into the commandline, Fish stores that function only for the current shell instance. funcsave writes that stored function to disk so that it will automatically be loaded on shell startup, thus always overriding the slow pacman-based fish_command_not_found.

[Joe23232]

Thanks mate, but what does this line: __fish_default_command_not_found_handler $argv mean actually?

[IlanCosman]

You should read about Fish basics in the Fish introduction. What you're specifically asking about though is functions.