Nixos-rebuild switch constantly fails

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1

Hello,
As per title, I’ve tried to run nixos-rebuild switch multiple times since yesterday, and it keeps failing. Today, I got the error linked to Sonic Pi which I shared below. Yesterday, it was due to Gimp.

Is it possible both packages became somehow corrupted (and, if so, how do I investigate?), or there is another underlying problem going on here?

warning: updating lock file '"/etc/nixos/flake.lock"':
• Updated input 'home-manager':
    'github:nix-community/home-manager/7c78e592a895f2f1921f0024848fe193e2f8518e?narHash=sha256-RXxejsGIWtJ5rJKLAm8Kh159euZHPMi7CtbOoHLsm2c%3D' (2025-07-17)
  → 'github:nix-community/home-manager/d0300c8808e41da81d6edfc202f3d3833c157daf?narHash=sha256-irfg7lnfEpJY%2B3Cffkluzp2MTVw1Uq9QGxFp6qadcXI%3D' (2025-07-18)
• Updated input 'nixpkgs':
    'github:nixos/nixpkgs/62e0f05ede1da0d54515d4ea8ce9c733f12d9f08?narHash=sha256-JHQbm%2BOcGp32wAsXTE/FLYGNpb%2B4GLi5oTvCxwSoBOA%3D' (2025-07-14)
  → 'github:nixos/nixpkgs/6e987485eb2c77e5dcc5af4e3c70843711ef9251?narHash=sha256-RKwfXA4OZROjBTQAl9WOZQFm7L8Bo93FQwSJpAiSRvo%3D' (2025-07-16)
building the system configuration...
error: builder for '/nix/store/9dss5c0ddh1mwl0fazcz72vx3w5cdrjs-sonic-pi-4.5.1.drv' failed with exit code 1;
       last 25 log lines:
       > [100%] Built target libsp_link
       > [ 98%] Performing install step for 'sp_link'
       > [100%] Built target libsp_link
       > Install the project...
       > -- Install configuration: ""
       > -- Installing: /build/source/app/server/beam/tau/priv/libsp_link.so
       > [ 99%] Completed 'sp_link'
       > [ 99%] Built target sp_link
       > [ 99%] Linking CXX executable sonic-pi
       > [100%] Built target sonic-pi
       > Compiling Erlang/Elixir files...
       > warning: the VM is running with native name encoding of latin1 which may cause Elixir to malfunction as it expects utf8. Please ensure your locale is set to UTF-8 (which can be verified by running "locale" in your shell) or set the ELIXIR_ERL_OPTIONS="+fnu" environment variable
       > warning: the VM is running with native name encoding of latin1 which may cause Elixir to malfunction as it expects utf8. Please ensure your locale is set to UTF-8 (which can be verified by running "locale" in your shell) or set the ELIXIR_ERL_OPTIONS="+fnu" environment variable
       > ==> logger_file_backend
       > Compiling 1 file (.ex)
       > Generated logger_file_backend app
       > ==> decimal
       > Compiling 4 files (.ex)
       > Generated decimal app
       > ==> mime
       > Compiling 1 file (.ex)
       > Generated mime app
       > ==> tau
       > escript: Not an archive file
       > ** (Mix) Could not compile dependency :telemetry, "/nix/store/zzgvmbmj7pal2jvjfqjdd8mnfckgd1gf-rebar3-3.25.0/bin/rebar3 bare compile --paths /build/source/app/server/beam/tau/_build/prod/lib/*/ebin" command failed. Errors may have been logged above. You can recompile this dependency with "mix deps.compile telemetry --force", update it with "mix deps.update telemetry" or clean it with "mix deps.clean telemetry"
       For full logs, run:
         nix log /nix/store/9dss5c0ddh1mwl0fazcz72vx3w5cdrjs-sonic-pi-4.5.1.drv
error: 1 dependencies of derivation '/nix/store/g9kh1c74slp1fi27x5i89g75l6kiynyi-system-path.drv' failed to build
error: 1 dependencies of derivation '/nix/store/xrhv97lv55rr1igbggplnmbqvrs1ql4i-nixos-system-nixos-25.11.20250716.6e98748.drv' failed to build
Command 'nix --extra-experimental-features 'nix-command flakes' build --print-out-paths '/etc/nixos#nixosConfigurations."nixos".config.system.build.toplevel' --no-link' returned non-zero exit status 1.
2

Removing both gimp and sonic-pi from configuration.nix, made the command run smoothly and quickly. However, I need and want both those apps.
How can I find out what’s going on?

3

This would be pretty unlikely.
But just to be sure can you run following command:

nix-store --verify --check-contents --repair

and than try again

4

The command ran for about three minutes, then I did the rebuild and got the same error as the one posted above.
What’s the insight?

5

Is it still the same package that fails? If so what happens when you remove that package from your config.
Also could you try a compiling benchmark to rule out any compiling issues (or even hardware issues). For that you can try out this: GitHub - phoronix-test-suite/phoronix-test-suite: The Phoronix Test Suite open-source, cross-platform automated testing/benchmarking software.
This is also in the nixpkgs

6

Running the same command with the same config will give the same result, not sure why we’re expecting anything different here. Nor am I sure why we’re talking about corruption or hardware issues, if sonic-pi is broken, just report it in the nixpkgs github repo.

And why did you remove gimp from your config?

7

sonic-pi is currently broken on unstable
https://hydra.nixos.org/job/nixos/trunk-combined/nixpkgs.sonic-pi.x86_64-linux

gimp was broken
https://hydra.nixos.org/job/nixos/trunk-combined/nixpkgs.gimp.x86_64-linux
fixed at: gimp: fix build with gettext 0.25 by wegank · Pull Request #425710 · NixOS/nixpkgs · GitHub

should be in unstable: Nixpkgs PR #425710 ("gimp: fix build with gettext 0.25") progress

I don’t think your nix store is at fault here.

2 Likes
8

Thank you. That’s what I was trying to understand and wasn’t sure where to check.
When something like this happen, is there a way to skip the update of the broken package(s) and keep on doing the rebuild with the others?

9

There isn’t a way to “skip” packages during the rebuild per se, because your system is always built from a specific nixpkgs commit (currently the one in which sonic-pi is broken). You could however take the packages from different revisions of nixpkgs. One way you could do that is by specifying another instance of nixpkgs at an earlier commit, where sonic-pi still built successfully and take the package from there.

Something like

inputs = {
    nixpkgs-older.url = "github:nixos/nixpkgs?ref=<your-ref>";
}
outputs = {...}@inputs

environment.systemPackages = [
    inputs.nixpkgs-older.legacyPackages.${pkgs.system}.sonic-pi
];

Do note that doing this seems to be generally discouraged, because it apparently evaluates nixpkgs twice, which makes your rebuild take longer IIUC.

As an aside: I cannot recommend the userscript at link enough. Just make sure to add the branch nixos-unstable in there. It’s the best way to track PR statuses in nixpkgs IMO.

2 Likes
10

This is very valuable knowledge. Thanks for sharing. :blush:
I will look into both in detail this weekend.
I will close this thread now then. Truly appreciated everyone’s help.

11

Before you do that, can you answer one question? Are you using "github:NixOS/nixpkgs/nixpkgs-unstable" or "github:NixOS/nixpkgs/nixos-unstable" for your nixpkgs input url?

12

I’m using this one.
Why?

13

Because I remember reading that nixpkgs-unstable goes through slightly fewer tests than nixos-unstable.

1 Like
14

It’s mostly the tests that assert the OS boots properly. It wouldn’t affect end-user software like this, buy yes, when using nixos use the nixos-* branches.

1 Like