Prebuilt index not found

[MarkusLohmayer]

I tried to setup comma together with the prebuilt index from
https://github.com/Mic92/nix-index-database
but I get Warning: Nix-index database does not exist.

I am on macOS and I have
nix-index-database.hmModules.nix-index as a home-manager module,
further I have programs.nix-index.enable = true;
and finally I have comma in home.packages.

You can see the precise setup here:

• https://github.com/MarkusLohmayer/nix-config/blob/main/flake.nix#L23
• https://github.com/MarkusLohmayer/nix-config/blob/main/flake.nix#L87
• https://github.com/MarkusLohmayer/nix-config/blob/main/home/home.nix#L21
• https://github.com/MarkusLohmayer/nix-config/blob/main/home/home.nix#L54

Thanks!

[eclairevoyant]

Yep, seems to be broken for this use case. Maybe it has to do with the wrapper that it's using.

[bestlem]

It also failed for me but I imported via the darwin module

so nix-index-database.darwinModules.nix-index
and comma installed system wide via environment.systemPackages

The command-not-found hook for nix-index does however work so the infrastructure is there.

[lancelet]

I have a similar setup, but was able to get around the problem by re-generating the index:

The error:

$ , cowsay neato
Warning: Nix-index database does not exist, either obtain a prebuilt database from https://github.com/Mic92/nix-index-database or try updating with `nix run 'nixpkgs#nix-index' --extra-experimental-features 'nix-command flakes'`.
nix-locate failed with: error: reading from the database at '/Users/jsm/.cache/nix-index/files' failed.
This may be caused by a corrupt or missing database, try (re)running `nix-index` to generate the database.
If the error persists please file a bug report at https://github.com/nix-community/nix-index.
caused by: No such file or directory (os error 2)

Workaround (doing what it suggests) - takes 10 minutes or so:

$ nix run 'nixpkgs#nix-index' --extra-experimental-features 'nix-command flakes'
+ querying available packages
+ generating index: 87498 paths found :: 42779 paths not in binary cache :: 00000 paths in queue
+ wrote index of 39,021,028 bytes

Then it works, but with a bunch of warnings about missing channels:

$ , cowsay neato
warning: Nix search path entry '/nix/var/nix/profiles/per-user/root/channels' does not exist, ignoring
warning: Nix search path entry '/nix/var/nix/profiles/per-user/root/channels' does not exist, ignoring
warning: Nix search path entry '/nix/var/nix/profiles/per-user/root/channels' does not exist, ignoring
warning: Nix search path entry '/nix/var/nix/profiles/per-user/root/channels' does not exist, ignoring
warning: Nix search path entry '/nix/var/nix/profiles/per-user/root/channels' does not exist, ignoring
warning: Nix search path entry '/nix/var/nix/profiles/per-user/root/channels' does not exist, ignoring
warning: Nix search path entry '/nix/var/nix/profiles/per-user/root/channels' does not exist, ignoring
warning: Nix search path entry '/nix/var/nix/profiles/per-user/root/channels' does not exist, ignoring
warning: Nix search path entry '/nix/var/nix/profiles/per-user/root/channels' does not exist, ignoring
warning: Nix search path entry '/nix/var/nix/profiles/per-user/root/channels' does not exist, ignoring
 _______
< neato >
 -------
        \   ^__^
         \  (oo)\_______
            (__)\       )\/\
                ||----w |
                ||     ||

I'm not sure about those warnings. Googling only says something about them not being relevant when flakes are used... (or something?)

I'm also concerned that the state it dumped in ~/.cache/nix-index/files requires a manual update, but that's less objectionable that the warnings.

[SuperSandro2000]

I'm not sure about those warnings. Googling only says something about them not being relevant when flakes are used... (or something?)

Those are because you have the directory in NIX_PATH but it doesn't exist. It is a warning from nix and has nothing to do with comma.

I'm also concerned that the state it dumped in ~/.cache/nix-index/files requires a manual update, but that's less objectionable that the warnings.

Yes, that's why many people use the index-db via flakes.

[ruffsl]

Maybe it has to do with the wrapper that it's using.

@eclairevoyant , thats what I noticed was missing from cat $(which ,) | head as compared to cat (which nix-locate) | head. So I just move comma out of my home manager and into environment.systemPackages and set rograms.nix-index-database.comma.enable = true; system wide, though I'm using NixOS. I suspect the wrapper may still work if I better understood how to best use module imports with home manager.

[eclairevoyant]

Sorry, I don't recall the details of this issue. I no longer use this comma or home-manager.

Instead, I wrote a oneliner replacement (pipe nix-locate into fzf) and yes, I use the nix-index-database NixOS module. Wouldn't be surprised if their h-m module is still broken.

[Artturin]

This works just fine

inputs.nix-index-database.nixosModules.nix-index
{ programs.nix-index-database.comma.enable = true; }

Don't add comma or nix-index to your path if you use either the h-m module or the nixos module

[Artturin]

This issue should be in the nix-index-database repo if it's in an issue with the wrapper or module