Czkawka - build from master workaround?

nokihe · December 27, 2025, 7:48am

I’m using the application “czkawka” for file management a lot and since switching to NixOS I’ve been hit by this bug:

Small previews and freezes in `czkawka_gui`

opened 08:53PM - 19 Dec 25 UTC

Due to a combination of circumstances, `czkawka_gui` has recently gained two new… regressions. # Small image previews This change is caused by this commit from gtk - https://gitlab.gnome.org/GNOME/gtk/-/merge_requests/8627 From what I understand, it fixes an issue with icons, but it also introduces "expected regressions". As you can see, Czkawka is one such regression, just like for example `gnome-music` - https://gitlab.gnome.org/GNOME/gnome-music/-/commit/a48f01d8cd66451dfdbe8abbd48fca179f96a28d I have been using this GtkImage widget since the GTK3 days and never had any real issues with it, so this behavioral change came as a surprise. <img width="1647" height="1183" alt="Image" src="https://github.com/user-attachments/assets/d5a083d1-604d-4f97-9e3e-bd7534a10bef" /> So the root cause here is GTK 4.20 - all versions of `czkawka_gui` ≤ 10.0 are affected by the same issue. This will be fixed in the upcoming 11.0 release. The fix is simply replacing `GtkImage` with `GtkPicture` in the project. ## Workarounds - Downgrade the OS so that the GTK version is lower than 4.20 - Use the patched czkawka version from the `master` branch # Infinite freezes during deleting/moving In this case, the bug was caused by an incorrect declaration of the `iter_next` function (see: https://github.com/gtk-rs/gtk4-rs/issues/2140) ``` fn iter_next(&self, iter: &TreeIter) -> bool; ``` This function signature suggests that `iter` is immutable. With Rust 1.86 and older, this did not cause visible issues (or at least I did not notice any). However, with newer versions, during various tests and while deleting files, I started hitting infinite loops. It turned out that `iter` is actually modified inside this function, which means the declaration should instead take a mutable argument ``` fn iter_next(&self, iter: &mut TreeIter) -> bool; ``` It also turned out that this bug had been present almost forever, and the real catalyst was some new or changed optimization introduced in Rust 1.87.0. ## Workarounds - Try using the latest `master` version of the program - I added `black_box` calls in some strategic(random) places to discourage aggressive compiler optimizations (this is a fragile workaround; a proper fix requires an updated `gtk4-rs`) - Compile the program with Rust 1.86.0 or older - the issue occurs far less frequently there - Compile the program with bumped(unstable) `gtk4-rs` package versions **Because of the above issues, I have lost trust in the stability that GTK claims to offer (at least on Linux) - gtk4-rs is a nice project, but creating binding to such project as gtk is very hard and maintaining invariants along entire codebase is almost impossible, so looks that better is to use some rust project instead.** **For that reason, I strongly recommend switching to Krokiet, which uses Slint and is nearly self-contained. As a result, it handles different systems much better and has a significantly lower chance of breaking due to random system package updates.**

The author says to workaround we either need to use the master branch or downgrade to GTK version lower than 4.20

Is there some easy to understand and follow guide or template for integrating that as a self managed nix package someone could point me to? Or is the suggested path for NixOS newbies rather to just build it inside a home-subfolder and call the binary with it’s path?

UPDATE: I just saw @qarmin also suggests switching to a differnt also included gui = “krokiet” - but that fails to start on my NixOS installation:

08:55:17.509 [INFO] czkawka_core::common::logger: Logging to file "/home/user/.cache/czkawka/krokiet.log" and terminal
08:55:17.515 [INFO] czkawka_core::common::logger: Krokiet version: 10.0.0, release mode, rust 1.91.1 (2025-11-07), os NixOS 25.11.0 (x86_64 64-bit), 20 cpu/threads, features(0): [], app cpu version: x86-64-v1 (SSE2), os cpu version: x86-64-v3 (AVX2)
08:55:17.515 [INFO] czkawka_core::common::config_cache_path: Config folder set to "/home/user/.config/krokiet" and cache folder set to "/home/user/.cache/czkawka"
08:55:17.515 [INFO] krokiet: Krokiet features(2): [winit_femtovg, winit_software]
08:55:17.524 [ERROR] log_panics: thread 'main' panicked at 'Failed to create main window: Could not initialize backend.
Error from Winit backend: Error initializing winit event loop: os error at /build/czkawka-10.0.0-vendor/winit-0.30.12/src/platform_impl/linux/wayland/event_loop/mod.rs:89: The wayland library could not be loaded
No backends configured.': krokiet/src/main.rs:77
   0: log_panics::Config::install_panic_hook::{{closure}}
   1: std::panicking::panic_with_hook
   2: std::panicking::panic_handler::{{closure}}
   3: std::sys::backtrace::__rust_end_short_backtrace
   4: __rustc::rust_begin_unwind
   5: core::panicking::panic_fmt
   6: core::result::unwrap_failed
   7: krokiet::main
   8: std::sys::backtrace::__rust_begin_short_backtrace
   9: std::rt::lang_start::{{closure}}
  10: std::rt::lang_start_internal
  11: main
  12: __libc_start_call_main
  13: __libc_start_main_alias_1
  14: _start

maybe somebody here can help with that?

UPDATE2: for the first workaround idea (building from master) this seems very related, but very difficult to understand for a non-NixOS-expert..

For the idea to switch to the newer GUI “krokiet” the software’s author @qarmin said it’s probably a packaging problem on NixOS and gave those links as explanations..:

UPDATE3:
It seems the NixOS build script for czkawka needs to be adapted similarly to what was done here:

does anybody know how I could get in contact with the maintainer of the NixOS czkawka package?

robsliwi · December 27, 2025, 4:26pm

Have you tried contacting via email? The NixOS Search gives you a nice mailto: with all maintainers of the package.

The other option would be to open an issue and ping them?

nokihe · December 27, 2025, 4:27pm

no I didn’t, since I didn’t know about it. Thanks about that hint where to find who the maintainers are:
@yanganto @0x4A6F → do you have accounts here in discourse? can you help me?

robsliwi · December 27, 2025, 4:29pm

Maybe the ux is not that clear, but if you click on the package czkawkathe package details are shown. Those include several links and a list of the maintainers with the option to mail them all

nokihe · December 28, 2025, 9:49pm

I’ve added a modified copy of the czkawka.nix package definition to my /etc/nixos/config*.nix setup:

{
  lib,
  atk,
  cairo,
  callPackage,
  fetchFromGitHub,
  gdk-pixbuf,
  glib,
  gobject-introspection,
  gtk4,
  pango,
  libGL,
  wayland,
  pkg-config,
  rustPlatform,
  stdenv,
  testers,
  wrapGAppsHook4,
  xvfb-run,
  versionCheckHook,
}:

let
  self = rustPlatform.buildRustPackage {
    pname = "czkawka";
    version = "10.0.0+";

    src = fetchFromGitHub {
      owner = "qarmin";
      repo = "czkawka";
      rev = "420d044b74c2472f9067ef64ca6763214ca14715";
      hash = "sha256-j2O9mBsujjdS/gsD3p8Lcry9qYu/SkJf+fttNT/hjQA=";
    };

    cargoHash = "sha256-6ZfHUnGmnOJ8k2uieiZ3SCvpQ4H47DAuvPas1KaTeg0=";

    nativeBuildInputs = [
      gobject-introspection
      pkg-config
      wrapGAppsHook4
    ];

    buildInputs = [
      atk
      cairo
      gdk-pixbuf
      glib
      gtk4
      pango
      libGL
      wayland
    ];

    nativeCheckInputs = [ xvfb-run ];

    strictDeps = true;

    doCheck = stdenv.hostPlatform.isLinux && (stdenv.hostPlatform == stdenv.buildPlatform);

    checkPhase = ''
      runHook preCheck
      xvfb-run cargo test
      runHook postCheck
    '';

    # Desktop items, icons and metainfo are not installed automatically
    postInstall = ''
      install -Dm444 -t $out/share/applications data/com.github.qarmin.czkawka.desktop
      install -Dm444 -t $out/share/icons/hicolor/scalable/apps data/icons/com.github.qarmin.czkawka.svg
      install -Dm444 -t $out/share/icons/hicolor/scalable/apps data/icons/com.github.qarmin.czkawka-symbolic.svg
      install -Dm444 -t $out/share/metainfo data/com.github.qarmin.czkawka.metainfo.xml
    '';

    nativeInstallCheckInputs = [
      versionCheckHook
    ];
    versionCheckProgram = "${placeholder "out"}/bin/czkawka_cli";
    versionCheckProgramArg = "--version";
    doInstallCheck = false;

    passthru = {
      tests.version = testers.testVersion {
        package = self;
        command = "czkawka_cli --version";
      };
      wrapper = callPackage ./wrapper.nix {
        czkawka = self;
      };
    };

    meta = {
      homepage = "https://github.com/qarmin/czkawka";
      description = "Simple, fast and easy to use app to remove unnecessary files from your computer";
      changelog = "https://github.com/qarmin/czkawka/raw/${self.version}/Changelog.md";
      license = with lib.licenses; [ mit ];
      mainProgram = "czkawka_gui";
      maintainers = with lib.maintainers; [
        yanganto
        _0x4A6F
      ];
    };
  };
in
self

That suffices to fix the czkawka_gui component (does no longer freeze when deleting files), but krokiet still fails to start, even though I added wayland to the dependency list:

Error from Winit backend: Error initializing winit event loop: os error at /build/czkawka-10.0.0+-vendor/winit-0.30.12/src/platform_impl/linux/wayland/event_loop/mod.rs:89: The wayland library could not be loaded