Nixos-rebuild switch does nothing (flakes)

user2358 · August 12, 2021, 1:10pm

I have started using flakes to manage system configuration a few months ago and it’s been going great. Today, I was creating a custom package which borked by nix store (my fault entirely). So I tried some commands to garbage collect and the system started working, but nixos-rebuild switch --flake .# did nothing (even when I changed various configs). I thought that the nix store broke and decided to create a new vm and installed a fresh copy of nixos. During nixos-install, I commented the home manager setup since it has some issues with new install and flakes. The install went great but when I logged in normally and issued rebuild-switch again, nothing happened again. No amount of changes in the config (either committed or dirty) resulted in action. The options -v or --show-trace also shows nothing.

I’m not sure what’s wrong, my config is here GitHub - addy419/configurations

NobbZ · August 12, 2021, 1:51pm

What exactly do you mean by “did nothing”?

What is the exit code when you try to rebuild?

Does it only happen on switch or can you use build or boot without issues?

What is your version of nix? What are the last ~10 lines when running using --verbose?

user2358 · August 12, 2021, 1:56pm

No, neither boot nor build work. rebuild switch with verbose shows no output (just that the config is dirty)

journal ctl (I’m sorry, the virtualbox clipboard sharing is not setup in new vm) shows

Nix version is 2.4pre20210802_47e96bb

user2358 · August 12, 2021, 2:06pm

Now that I look at it it’s segfault, the issue is here 'nix build . -L -vvv' terminated by signal SIGSEGV (Address boundary error) · Issue #5100 · NixOS/nix · GitHub

NobbZ · August 12, 2021, 2:07pm

As far as I understand, the hardest part is to find where the attributes are missing…

user2358 · August 12, 2021, 2:09pm

After I removed the mkDerivation, It started working. Someone described it as segfault when mkDerivation has no name attribute, I’ll recheck by adding a name attribute segmentation fault in `libnixexpr.so` when derivation has no `name` attribute · Issue #5113 · NixOS/nix · GitHub

NobbZ · August 12, 2021, 2:15pm

So I can only find this one mkDerivation in your code, and indeed, it is missing the pname:

github.com

addy419/configurations/blob/94f8b23f87b09e6b17396742dd38d2d46695ccba/modules/desktop/terminal.nix#L3-L11

    
      
          let wcwidth-icons = with pkgs; stdenv.mkDerivation rec {
                src = fetchurl {
                      url = "https://github.com/powerman/wcwidth-icons/archive/refs/tags/v${version}.tar.gz";
                      sha256 = "1j87159859mwsdvi12gal6l81jivy4pjk62f4h016wmv866ybphf";
                };
                version = "0.2.2";
                installFlags = [ "LIBDIR=$(out)/lib" ];
          #      buildInputs = [ gnumake ];
          };

user2358 · August 12, 2021, 2:22pm

Yes, adding name fixed the segfault. Thank you for the help.