Dotty Documentation


Building Dotty with Eclipse


You can setup Eclipse by using Scala IDE for Eclipse to run Dotty. Alternatively you can download your Eclipse distribution of choice and enable the Scala IDE from the Eclipse Marketplace, separately.

  1. Clone Dotty's repository from Github (and run sbt managedSources as described in Getting Started)
  2. Generate the Eclipse configuration files:
$ sbt eclipse
  • Note: It is recommended to change the default output folder (in Properties > java build path > Source) to dotty/classes instead of dotty/bin because dotty/bin is reserved for shell scripts.

Optional: if you have CLASSPATH defined:

  1. Update your classpath to contain any new required external libraries to run ./bin/dotc, ./bin/dotr outside of Eclipse.

  2. Open the Run Configurations tab, and edit the tests configuration so that it contains a CLASSPATH variable which reflects the current CLASSPATH.

Import to Eclipse

First step is to import dotty to Eclipse. This is done by selecting File > Import from the menu and selecting Existing Projects into Workplace.

On the next window, select the bare minimum configuration to run Dotty. You will need the compiler, library and the interfaces.


To run/debug Dotty you have to create a new configuration from Run > Run Configurations. First select the project on the package explorer and then select the aforementioned option. On the Main tab you must have dotty-compiler for the Project and for the Main class. Specify the arguments you want for the compiler on the Arguments tab (e.g, flags and source files) and then proceed to the Classpath tab. There you must specify three Bootstrap Entries which are the compiler, interfaces and the library as shown in the screenshot below. Additionally you need to specify the scala-asm library as an external jar dependency. This can be found on your local ~/.ivy2/cache/ directory.

The compiler can be run and debugged using the same configuration.