Hacker News Reader

Comment by kreetx | Hacker News Reader

NixOS is difficult to start out with, and great after that :p.

Started using it recently for work and it has been reliable thus far. The only issue that I've had was when upgrade to Mojave where a patch was needed. But to do this you clone the nixpkgs repo (of package descriptions), cherry pick the fix, point the package manager to the repo, and it continues to work.

One can create docker images from the machine definitions, so the target need not be nixos, but anything that runs docker.

But if you're not the type of person to pull through difficulties then this distro is not for you (yet).

View on HN

Another approach is not to patch nixpkgs at all, but just to "override" packages in Nixpkgs outside of the repository, and build them from your own project directories.

A simple example: I wanted to build FFMPEG, but with non-free libraries enabled (which is not the default). Rather than edit "ffmpeg-full" in the nixpkgs repo, I just overrode it:

    # default.nix (in some project directory; call "nix build -f ." to run it)
    with nixpkgs;
    {
      my-ffmpeg =
        let overrides = {
        nonfreeLicensing = true;
        fdkaacExtlib = true;
        ffplayProgram = false;
        qtFaststartProgram = false;
      };
      attrs = {
        name="my-ffmpeg-" + ffmpeg.version;
      };
    in
      ffmpeg-full.override overrides // attrs;
    }

You are ahead of me! Thank you for the example :)

You're welcome!

One last tip... If you build this way, it will write everything to /nix/store, but it won't install it into your local profile. However, the 'nix-build' process creates a 'result' symlink in your project directory which points at the package you just built. So Calling 'nix-env -i ./result' ought to install it into your profile as well.

You can also just call `nix-env -i .` to build and install in one go.

Ah! thanks for that.

You can also use an overlay

Thanks, I've heard the term 'overlay' but I haven't learned quite that much yet. I'll look into this.

I haven't ever tried this myself, but I was under the impression that the `--arg` and `--argstr` arguments to nix-env were supposed to let you change build options. So could you not say `nix-env -iA nixpkgs.ffmpeg-full --arg nonfreeLicensing true --arg fdkaacExtlib true --arg ffplayProgram false --arg qtFaststartProgram false`?

You may well be right. In my first attempts, I did try various combinations of `--arg` and `--argstr`, but I never succeeded in getting a proper build. That's why I ended up using the override approach instead. I understand a little bit more (very little!) about Nix now, so perhaps I should give it another try.

Reply on news.ycombinator.com