Skip to content

Unreproducible Package: flutter.passthru.unwrapped #575354

Closed

Description

@me-and

Nixpkgs Revision

8edc0c7

Introduction

Building flutter.passthru.unwrapped multiple times does not yield bit-by-bit identical
results, complicating the detection of Continuous Integration (CI) breaches. For
more information on this issue, visit reproducible-builds.org.

Fixing bit-by-bit reproducibility also has additional advantages, such as
avoiding hard-to-reproduce bugs, making content-addressed storage more effective
and reducing rebuilds in such systems.

Steps to reproduce

1. Build the package

This step will build the package. Specific arguments are passed to the command
to keep the build artifacts so we can compare them in case of differences.

Execute the following command:

nix-build '<nixpkgs>' -A flutter.passthru.unwrapped && nix-build '<nixpkgs>' -A `flutter.passthru.unwrapped` --check --keep-failed

Or using the new command line style:

nix build nixpkgs#flutter.passthru.unwrapped && nix build nixpkgs#flutter.passthru.unwrapped --rebuild --keep-failed

2. Compare the build artifacts

If the previous command completes successfully, no differences were found and
there's nothing to do, builds are reproducible.
If it terminates with the error message error: derivation '<X>' may not be deterministic: output '<Y>' differs from '<Z>', use diffoscope to investigate
the discrepancies between the two build outputs. You may need to add the
--exclude-directory-metadata recursive option to ignore files and directories
metadata (e.g. timestamp) differences.

nix run nixpkgs#diffoscopeMinimal -- --exclude-directory-metadata recursive <Y> <Z>

3. Examine the build log

To examine the build log, use:

nix-store --read-log $(nix-instantiate '<nixpkgs>' -A flutter.passthru.unwrapped)

Or with the new command line style:

nix log $(nix path-info --derivation nixpkgs#flutter.passthru.unwrapped)

Diffoscope log

--- /nix/store/vaqda7sg0xc5a66yafvnvm762w3aj904-flutter-3.47.4-unwrapped
+++ /nix/store/vaqda7sg0xc5a66yafvnvm762w3aj904-flutter-3.47.4-unwrapped.check
│   --- /nix/store/vaqda7sg0xc5a66yafvnvm762w3aj904-flutter-3.47.4-unwrapped/share
├── +++ /nix/store/vaqda7sg0xc5a66yafvnvm762w3aj904-flutter-3.47.4-unwrapped.check/share
│ │   --- /nix/store/vaqda7sg0xc5a66yafvnvm762w3aj904-flutter-3.47.4-unwrapped/share/bash-completion
│ ├── +++ /nix/store/vaqda7sg0xc5a66yafvnvm762w3aj904-flutter-3.47.4-unwrapped.check/share/bash-completion
│ │ │   --- /nix/store/vaqda7sg0xc5a66yafvnvm762w3aj904-flutter-3.47.4-unwrapped/share/bash-completion/completions
│ │ ├── +++ /nix/store/vaqda7sg0xc5a66yafvnvm762w3aj904-flutter-3.47.4-unwrapped.check/share/bash-completion/completions
│ │ │ │   --- /nix/store/vaqda7sg0xc5a66yafvnvm762w3aj904-flutter-3.47.4-unwrapped/share/bash-completion/completions/flutter.bash
│ │ │ ├── +++ /nix/store/vaqda7sg0xc5a66yafvnvm762w3aj904-flutter-3.47.4-unwrapped.check/share/bash-completion/completions/flutter.bash
│ │ │ │ @@ -52,9 +52,9 @@
│ │ │ │      IFS="$si"
│ │ │ │    }
│ │ │ │    compctl -K __flutter_completion flutter
│ │ │ │  fi
│ │ │ │  
│ │ │ │  ###-end-flutter-completion-###
│ │ │ │  
│ │ │ │ +## Generated 2026-10-17 18:29:41.463435Z
│ │ │ │ -## Generated 2026-09-23 14:51:04.546716Z
│ │ │ │  ## By /nix/store/vaqda7sg0xc5a66yafvnvm762w3aj904-flutter-3.47.4-unwrapped/bin/cache/flutter_tools.snapshot
│ │   --- /nix/store/vaqda7sg0xc5a66yafvnvm762w3aj904-flutter-3.47.4-unwrapped/share/zsh
│ ├── +++ /nix/store/vaqda7sg0xc5a66yafvnvm762w3aj904-flutter-3.47.4-unwrapped.check/share/zsh
│ │ │   --- /nix/store/vaqda7sg0xc5a66yafvnvm762w3aj904-flutter-3.47.4-unwrapped/share/zsh/site-functions
│ │ ├── +++ /nix/store/vaqda7sg0xc5a66yafvnvm762w3aj904-flutter-3.47.4-unwrapped.check/share/zsh/site-functions
│ │ │ │   --- /nix/store/vaqda7sg0xc5a66yafvnvm762w3aj904-flutter-3.47.4-unwrapped/share/zsh/site-functions/_flutter.bash
│ │ │ ├── +++ /nix/store/vaqda7sg0xc5a66yafvnvm762w3aj904-flutter-3.47.4-unwrapped.check/share/zsh/site-functions/_flutter.bash
│ │ │ │ @@ -52,9 +52,9 @@
│ │ │ │      IFS="$si"
│ │ │ │    }
│ │ │ │    compctl -K __flutter_completion flutter
│ │ │ │  fi
│ │ │ │  
│ │ │ │  ###-end-flutter-completion-###
│ │ │ │  
│ │ │ │ +## Generated 2026-10-17 18:29:41.463435Z
│ │ │ │ -## Generated 2026-09-23 14:51:04.546716Z
│ │ │ │  ## By /nix/store/vaqda7sg0xc5a66yafvnvm762w3aj904-flutter-3.47.4-unwrapped/bin/cache/flutter_tools.snapshot

Notify maintainers

@ericdallo, @RossComputerGuy, @FlafyDev, @hacker1024, @mkg20001


Note for maintainers: Please tag this issue in your pull request description. (i.e. Resolves #ISSUE.)

I assert that this issue is relevant for Nixpkgs

Is this issue important to you?

Add a 👍 reaction to issues you find important.

Activity

  1. linked a pull request that will close this issueflutter: improve build determinism #575372on Oct 18, 2026
  2. added a commit that references this issue on Oct 22, 2026
    80619c8
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Metadata

Metadata

Assignees

No one assigned

    Labels

    Projects

    No projects

      Milestone

      No milestone

      Relationships

      None yet

      Development

      No branches or pull requests

      Issue actions