code-cursor: aarch64-linux build dependency on ffmpeg fails

[jmettes]

Nixpkgs version

• Unstable (25.05)

Describe the bug

On aarch64-linux NixOS, installing code-cursor from unstable channel fails. It looks like it's trying to pull in
https://github.com/NixOS/nixpkgs/blob/4f0dadbf38ee4cf4cc38cbc232b7708fddf965bc/pkgs/applications/networking/browsers/vivaldi/ffmpeg-codecs.nix

But it looks like that's for x86_64-linux platform only.

Steps to reproduce

$ sudo nixos-rebuild switch
building Nix...
building the system configuration...
error:
       … while calling the 'head' builtin
         at /nix/var/nix/profiles/per-user/root/channels/nixos/lib/attrsets.nix:1:35876:
       … while evaluating the attribute 'value'
         at /nix/var/nix/profiles/per-user/root/channels/nixos/lib/modules.nix:1:37175:
       … while evaluating the option `system.build.toplevel':

       … while evaluating definitions from `/nix/var/nix/profiles/per-user/root/channels/nixos/nixos/modules/system/activation/top-level.nix':

       … while evaluating the option `system.systemBuilderArgs':

       … while evaluating definitions from `/nix/var/nix/profiles/per-user/root/channels/nixos/nixos/modules/system/activation/activatable-system.nix':

       … while evaluating the option `system.activationScripts.etc.text':

       … while evaluating definitions from `/nix/var/nix/profiles/per-user/root/channels/nixos/nixos/modules/system/etc/etc-activation.nix':

       … while evaluating definitions from `/nix/var/nix/profiles/per-user/root/channels/nixos/nixos/modules/system/etc/etc.nix':

       … while evaluating the option `environment.etc.dbus-1.source':

       (stack trace truncated; use '--show-trace' to show the full, detailed trace)

       error: Package ‘chromium-codecs-ffmpeg-extra-115541’ in /nix/store/gv749bbggig1nd1hlp62x75jxsxqp2s5-nixos/nixos/pkgs/applications/networking/browsers/vivaldi/ffmpeg-codecs.nix:30 is not available on the requested hostPlatform:
         hostPlatform.config = "aarch64-unknown-linux-gnu"
         package.meta.platforms = [
           "x86_64-linux"
         ]
         package.meta.badPlatforms = [ ]
       , refusing to evaluate.

       a) To temporarily allow packages that are unsupported for this system, you can use an environment variable
          for a single invocation of the nix tools.

            $ export NIXPKGS_ALLOW_UNSUPPORTED_SYSTEM=1

          Note: When using `nix shell`, `nix build`, `nix develop`, etc with a flake,
                then pass `--impure` in order to allow use of environment variables.

       b) For `nixos-rebuild` you can set
         { nixpkgs.config.allowUnsupportedSystem = true; }
       in configuration.nix to override this.

       c) For `nix-env`, `nix-build`, `nix-shell` or any other Nix command you can add
         { allowUnsupportedSystem = true; }
       to ~/.config/nixpkgs/config.nix.

Expected behaviour

Expected to install, based on platform tag availability

Screenshots

No response

Relevant log output

Additional context

No response

System metadata

$ nix-shell -p nix-info --run "nix-info -m"
 - system: `"aarch64-linux"`
 - host os: `Linux 6.12.21, NixOS, 25.05 (Warbler), 25.05pre780010.063dece00c5a`
 - multi-user?: `yes`
 - sandbox: `yes`
 - version: `nix-env (Nix) 2.24.13`
 - channels(root): `"nixos"`
 - nixpkgs: `/nix/var/nix/profiles/per-user/root/channels/nixos`

$ sudo nix-channel --list
nixos https://nixos.org/channels/nixos-unstable

Notify maintainers

@sarahec

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[sarahec]

Looks like the vivaldi-ffmpeg-codecs derivation hasn't been updated recently. (latest changes: 10 months, 2 years).

These codecs are available for arm64. It should be a matter of adding and selecting the proper sources to make this work again. This would solve your problem.

[sarahec]

Blocked by #304751

[sarahec]

@jmettes that should fix things