Anyone with experience using NixOS to create a Lemmy instance, please share any caveats and troubleshooting tips you have.

  • ericjmorey@lemmy.worldOP
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    1 year ago

    Is this sort of lag the nature of package managers that will inherently be part of NixOS and nixpk?

    • neoney@lemmy.neoney.dev
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      1 year ago

      Nixpkgs is by nature fully reproducible and declarative - that means you can’t write a nix package to just build from master branch. You also have to specify the sha256 hash to absolutely make sure the source is the same for everyone.
      With flakes, it’s a bit easier, because if the package you’re trying to build has a flake, you can just update it in your own lockfile and it will be rebuilt from the latest version.
      If using something from nixpkgs, you have to wait (or PR yourself) for someone to PR the update, or you can also use overrideAttrs to do a “private” fix.
      For example, I’m using the wlsunset program, but wanted to build from a different branch, so I did this:

            (wlsunset.overrideAttrs (old: {
              src = fetchFromSourcehut {
                owner = "~kennylevinsen";
                repo = old.pname;
                rev = "81cfb0b4f8e44db9e5ecb36222a24d53a953e6aa";
                sha256 = "sha256-Lxuhsk4/5EHuKPkBbaRtCCQ/LFvIxyc+VQYEoaVT484=";
              };
            }))
      

      This just changes the source attribute to another commit and another sha hash, and it works fine.

      • neoney@lemmy.neoney.dev
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        1 year ago

        In the end, the lag is just caused by the fact that it has to work. You never want to get some broken version that you want to avoid, so nix packages are always tested with the new versions, because it may turn out they may need some patching for that version, or they have some new dependencies.

    • neoney@lemmy.neoney.dev
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      1 year ago

      While we were talking I updated lemmy-server using overrideAttrs for my own use. It’s honestly not that hard. You change the commit, specify some random incorrect hashes, build it, nix screams at you that the hash is incorrect (and generously provides the correct one), put the correct hash, and build again. Done.

        • neoney@lemmy.neoney.dev
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          1 year ago

          The hash isn’t there for security, it’s to make sure the code you’re building against doesn’t randomly change which could make the derivation fail to compile. For example, for the source, you can specify a literal HTTP download from a URL, and that file could be changed by the host at any given time, so it’s there as a safeguard.