Buck - life is too short to spend a minute for each build

Gradle is too slow, Ant is too basic. Buck is fast and super-configurable and I’d like to tell you how I use it for Android development.

I own a pretty old thinkpad laptop so I don’t expect the builds to be too fast. Ant used to spend 10..40 seconds for each build on my laptop depending on how large the project is. Gradle takes about a minute in average and that’s too long for me - I just lose focus when I just sit and wait for the build results.

I had great expectations about Bazel, but it doesn’t have Android support yet. And then I’ve heard about Buck. I tried it and it was so great that I could not believe it.

how fast is this buck?

Let me show you some numbers for each of the build systems. It’s not a real benchmark made in the vacuum, it’s just a picture of my average workflow with my normal apps running in the background. I created a minimal empty project with a single activity, some XML resources and a few lines of code. Here’s the commands I used to generate project structure:


android create project -p ant-example -k com.example.buildsystem -n BuildSystemTest -a MainActivity -t android-21


android create project -p gradle-example -k com.example.buildsystem -n BuildSystemTest -a MainActivity -t android-21 -g -v 1.1

Buck (using my own wrapper, see about it below):

buckbonejava com.example.buildsystem buck-example

Then I tried a clean build, an incremental build and a no-op build. For all builds I used ‘ant debug’, ‘gradle assembleDebug’ and ‘buck build app’ commands, I measured time with ‘time’ command (instead of using the numbers printed by each build system, those numbers are a bit lower).

Now, let’s try a larger project. I simply added some fake methods in five more source files, 3000 LOC in total. Looks like a common number for a single-person project. Incremental build times are (for the addition of 3000 LOC):

So Buck is ~10 times faster than other build systems for my normal workflow. And I actually never seen it to take more than 5 seconds for my (relatively simple) projects.

how can it be true?

Technical details of Buck are described here. It optimizes everything - it keeps jvm running in the nailgun server, it uses threads, it caches a lot, it uses an optimized ‘dx’ utility etc etc. They even seem to have a separate app that updates your code in the ‘live’ mode, so you don’t have to pack the APK and install it (in fact, now ‘adb install’ is one of the longest build steps I have now!).

where’s the catch?

Buck has outdated documentation. You have to spend time reading the issue trackers and looking for the ansers.

Buck seems to have a small community. Not so many Stackoverflow answers, not so many articles, not so many tutorials.

Buck ‘quickstart’ command is far from what you expect from the app skeleton generator.

In Buck you have to write most of the build scripts manually. It gives you power, but it takes away the convenience. E.g. for your dependencies you have to download them, put into some folder, create rules that point to the JARs, include those rules as a dependency.

Ah, Buck seems to have no support for Windows, but well, I don’t care about Windows.

So Buck can be a problem for newcomers, but if you learn it - you get a very fast build system you can totally control. No magic behing the scenes.

finally, what’s that buckbonejava command?

Since I often play with app ideas - I want to start a new app quickly, write some code and see the results as quickly as possible. Buck fits perfectly here.

So I spent some time to make a tiny Bash script that generates the Buck android project. Just give it a package name and tell where to put the generated sources.

Buckbone is available at https://github.com/zserge/buckbone

In your project the sources will be at java/my/package/name/, and resources will be at res/my/package/name/res/values/strings.xml etc. Just go edit those and run ‘buck install app’ or ‘buck build app’.

As a nice bonus I’ve added the maven macro so you can include the dependencies like:

maven('com.squareup:otto:1.3.7') # that's how you define your maven library
maven('com.squareup.okhttp:okhttp:2.4.0') # that's how you define your maven library

    deps = [
        ':otto',   # this matches the library name 

AARs and JARs are supported. You can run ‘buck fetch app’ to download those dependencies. Or it will download them on the next ‘buck build’ cycle. Similar to Gradle, huh?

Next, I like Kotlin language a lot and I want it to become my primary language for Android development. So far I only used Kotlin with Gradle and it was painful. The language speeds up my code writing, but each build took over one minute. I tried Kotlin with Buck and got my build times reduced to 15 seconds, which is the best I could have expected from Java+Ant in the past. Kotlin generator is still experimental, but you may try it using buckbonekotlin instead of buckbonejava to start your Kotlin android projects right now.

I also tried to manually run nailgun for the Kotlin compiler and got the app built in about 5 seconds, I could not even dream about such a small number. But this approach uses too many hardcoded paths that I can’t recommend it yet for normal usage and I can’t make a generic wrapper.

extending Buck

At the moment Buck is very hard to extend and it’s not documented. So no Buck plugins yet (and that’s why it seems so hard for me to add Kotlin support).

Also I’m not sure how the top-level Buck configuration can be accessed from within the Buck script, but if that’s possible - it could simplify things a lot. E.g. compiler paths could be defined in the top-level config, and other build scripts would reuse those.

I’m still very new to Buck, but if you have any suggestions how to create a Buck project that would use Kotlin or any other compiler (Scala, Groovy, Clojure) with nailgun and Buck - please share your thoughts. Also if you have an idea to improve my buckbone scripts - send me pull requests.

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May 27, 2015

See also: kotlin - a new hope and more.