Kruftle

Reclaim your disk. Kill the cruft.

kruftle.dizitart.com  ·  Download  ·  Manual

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A developer machine accumulates build output the way a workshop accumulates sawdust. A target/ here, a node_modules/ there, a build/ in every Flutter app — none of it precious, all of it invisible, and collectively tens of gigabytes.

Kruftle scans a directory, works out what every project underneath it is built with, and reclaims that space by running each toolchain's own clean command.

• cargo clean for Rust crates
• flutter clean for Flutter apps
• mvn clean for Maven projects
• ./gradlew clean for Gradle projects
• go clean for Go projects
• dotnet clean for .NET projects
• swift package clean for Swift packages
• mix clean for Elixir projects

and so on, for 42 toolchains in total.

Why the tool's own command

Because rm -rf on a guessed directory name is how people lose work.

cargo clean knows which files in target/ are Cargo's. A shell glob does not. Kruftle only ever deletes a directory outright when the SDK for that project genuinely is not installed, the directory name is on a per-stack allow-list, and you have ticked a box saying so for that run.

What it does

• Finds every project, including the ones nested inside other projects — the Rust crate in a Flutter app has build output that flutter clean will never touch.
• Detects the toolchain and whether it is installed, so you know before you start which projects will get a proper clean and which are offered a fallback.
• Dry run first, with a real measurement of what would be freed. Or skip it.
• Choose what runs. Select all, none, or exactly the projects you mean.
• Cleans in parallel, projects at a time, and reports what was actually freed rather than what was predicted.
• Logs everything and exports it when you want to know what happened.

Safety

Disk cleanup tools get one chance to earn trust. Kruftle:

• refuses to run on /, your home directory, or any system path, and that refusal cannot be waived
• refuses a path near the root of its drive too — but that one is a guess at intent, not a danger, so it asks instead: a mapped network drive or a mounted volume puts a real codebase at Z:\ or /mnt/work, and Kruftle shows you the path and what a scan does, and proceeds only if you say so
• never follows a symlink, and never deletes through one
• deletes only directory names a matched stack explicitly declares — never a glob, never a pattern you typed
• re-checks every rule at the moment of deletion, not just when planning
• skips anything git tracks, because some repos commit their build/ and a rebuild will not bring that back
• asks before every category of raw deletion, every run

Each of those has a test that fails closed.

Supported stacks

42 toolchains, detected by marker file and cleaned with that toolchain's own command.

Family	Stacks
Systems	Rust · Go · Zig · Nim · Crystal · D · Fortran · Ada
Native / C++	CMake · Make · Bazel · Meson · Ninja · Autotools · Conan · vcpkg · PlatformIO
JVM & .NET	Maven · Gradle · sbt · Clojure · .NET
Dart	Flutter · Dart
Apple	Xcode · Swift Package
Web & scripting	Node.js · Deno · PHP / Composer · Python · Ruby · Perl
Functional	Haskell · Cabal · Erlang · Elixir · OCaml · Gleam
Data & infra	Julia · R · Terraform · Unity

Adding another is one file and one list entry — see lib/src/core/registry/. If your stack is missing, open an issue and it is usually a short PR away.

How it compares

kondo describes itself, in its own README, as "essentially rm -rf with a prompt" — a legitimate design, and the reason it is faster than Kruftle. It is also the one thing Kruftle deliberately does not do.

Kruftle compared to kondo and npkill, including where those tools are the better choice.

Install

Download the build for your platform from Releases.

• macOS — the .dmg; drag Kruftle to Applications. Only for the first install: updates after that replace the app in place, with no disk image.
• Windows — the -setup.exe. It installs for you alone, under %LOCALAPPDATA%\Programs, and needs no administrator. Add /ALLUSERS for a machine-wide install.
• Linux — the .deb, the .AppImage (chmod +x it first), or the .tar.gz unpacked anywhere you can write.

Builds are currently unsigned, so the first launch needs one extra step:

• macOS — xattr -dr com.apple.quarantine /Applications/Kruftle.app
• Windows — SmartScreen → More info → Run anyway

Updating

Kruftle updates itself. It checks Releases at launch, offers the new version, verifies the download against the release's published SHA-256, and unpacks it over the installed copy when you restart — no installer, nothing to drag. You can also ask at any time: Settings → Updates → Check for updates now.

The one case that still needs an installer is a copy installed somewhere you cannot write — a machine-wide C:\Program Files install, or a .deb under /usr. Those are offered their own packaging's installer instead, because replacing those files needs a password and doing that behind a progress bar would be worse than asking.

Building from source

flutter pub get
flutter test
flutter run -d macos   # or -d windows, -d linux

License

GPL-3.0-or-later. See LICENSE.