Installing Stainless

Stainless can be very easily integrated with an sbt build by using the sbt-stainless plugin.

If you are not using sbt, then Stainless is probably easiest to build on Linux-like platforms, but read on regarding other platforms.

Due to its nature, this documentation section may not always be up to date; we welcome pull requests with carefully written and tested improvements to the information below.



Setting up a sbt build file to use stainless it’s a simple 4-steps procedure:

  1. Start by installing an external solver (see Section “External Solvers”).
  2. Add the sbt-stainless plugin together with the required resolver to your project/plugins.sbt
resolvers += Resolver.url(“LARA sbt plugins releases",url(""))(Resolver.ivyStylePatterns)
addSbtPlugin("ch.epfl.lara" % "sbt-stainless" % "<insert-version>")

Check the sbt-stainless bintray repository for the available versions.

  1. In your project’s build file, enable the StainlessPlugin on the modules that should be verified by stainless. Below is an example:
// build.sbt
lazy val algorithm = (project in file("algorithm"))
.enablePlugins(StainlessPlugin) // <-- Enabling stainless verification on this module!

Note that if you are using .scala build files you need to use the fully qualified name ch.epfl.lara.sbt.stainless.StainlessPlugin. Also, because stainless accepts a subset of the Scala language, you may need to refactor your build a bit and code to successfully use stainless on a module.

  1. After modifying the build, type reload if inside the sbt interactive shell. From now on, when executing compile on a module where the StainlessPlugin is enabled, stainless will check your Scala code and report errors in the shell (just like any other error that would be reported during compilation).

That’s all there is to it. However, the sbt-stainless plugin currently has the following limitations you should know about:

  • No incremental compilation support. All sources (included the stainless-library sources) are recompiled at every compile execution.
  • The plugin only supports vanilla Scala. To track sbt support in dotty you can follow issue #178.

Also, note that the plugin offers a stainlessIsEnabled setting that can help experimenting with stainless. The stainlessIsEnabled setting is set to true by default, but you can flip the flag to false by typing set every stainlessIsEnabled := false while inside the sbt interactive shell.

Linux & Mac OS-X

Get the sources of Stainless by cloning the official Stainless repository:

$ git clone
Cloning into 'stainless'...
// ...
$ cd stainless
$ sbt clean universal:stage
// takes about 1 minute

The compilation will automatically generate the following two bash scripts:

  1. frontends/scalac/target/universal/stage/bin/stainless-scalac that will use the scalac compiler as frontend,
  2. frontends/stainless-dotty/target/universal/stage/bin/stainless-dotty that uses the dotc compiler as frontend (experimental).

You may want to introduce a soft-link from frontends/scalac/target/universal/stage/bin/stainless-scalac to stainless:

$ ln -s frontends/scalac/target/universal/stage/bin/stainless-scalac stainless

These scripts work for all platforms and allow additional control over the execution, such as passing JVM arguments or system properties:

$ frontends/scalac/target/universal/stage/bin/stainless-scalac -Dscalaz3.debug.load=true -J-Xmx6G --help

Note that Stainless is organized as a structure of several projects. The main project lives in core while the two available frontends can be found in frontends/scalac and frontends/dotty. From a user point of view, this should most of the time be transparent and the build command should take care of everything.


Get the sources of Stainless by cloning the official Stainless repository. You will need a Git shell for windows, e.g. Git for Windows.

$ git clone
Cloning into 'stainless'...
// ...
$ cd stainless
$ sbt clean universal:stage
// takes about 1 minutes

Compilation will automatically generate the following two bash scripts:

  1. frontends/scalac/target/universal/stage/bin/stainless-scalac.bat that will use the scalac compiler as frontend,
  2. frontends/stainless-dotty/target/universal/stage/bin/stainless-dotty.bat that uses the dotc compiler as frontend (experimental).

External Solvers

Inox, the solving backend for Stainless, relies on SMT solvers for reasoning about quantifier-free formulas. See inox’ solver documentation for more information on how to get/install these solvers.

Note that for the Native Z3 API to be available, you will have to place the jar produced by building ScalaZ3 into unmanaged/scalaz3-$os-$arch-$scalaVersion.jar.

Running Tests

Stainless comes with a test suite. Use the following commands to invoke different test suites:

$ sbt test
$ sbt it:test

It’s also possible to run tests in isolation, for example, the following command runs Extraction tests on all files in termination/looping:

$ sbt 'it:testOnly *ExtractionSuite* -- -z "in termination/looping"'

Building Stainless Documentation

To build this documentation locally, you will need Sphinx ( ), a restructured text toolkit that was originally developed to support Python documentation.

After installing sphinx, run sbt previewSite. This will generate the documentation and open a browser.

The documentation resides in the core/src/sphinx/ directory and can also be built without sbt using the provided Makefile. To do this, in a Linux shell go to the directory core/src/sphinx/, type make html, and open in your web browser the generated top-level local HTML file, by default stored in src/sphinx/_build/html/index.html. Also, you can open the *.rst documentation files in a text editor, since they are human readable in their source form.

Using Stainless in Eclipse


You first need to tell sbt to globally include the Eclipse plugin in its known plugins. To do so type

$ echo "addSbtPlugin(\"com.typesafe.sbteclipse\" % \"sbteclipse-plugin\" % \"2.4.0\")" >> ~/.sbt/0.13/plugins/plugins.sbt

In your Stainless home folder, type: `sbt clean compile eclipse`

This should create all the necessary metadata to load Stainless as a project in Eclipse.

You should now be able to import the project into your Eclipse workspace. Don’t forget to also import dependencies (the dotty and cafebabe projects, found somewhere in your ~/.sbt directory).

For each run configuration in Eclipse, you have to set the ECLIPSE_HOME environment variable to point to the home directory of your Eclipse installation. To do so, go to

Run -> Run Configuration

and then, after picking the configuration you want to run, set the variable in the Environment tab.

If you want to use ScalaTest from within Eclipse, download the ScalaTest plugin. For instructions, see Using ScalaTest with Eclipse. Do NOT declare your test packages as nested packages in separate lines, because ScalaTest will not see them for some reason. E.g. don’t write

package stainless
package test
package myTestPackage

but instead

package stainless.test.myTestPackage