Troubleshooting Installation Problems

Diagnostic Tools

  • The Error Log will typically contain useful information if something goes wrong. You can see it by going to the Window menu, then Show View → Error Log (or Show View → Other… → Error Log). If you can’t identify the log entry corresponding to your problem, clear the log and provoke the problem again.

    If the log contains an exception trace, you might get a hint about what’s wrong by looking at the last exception in the chain of exceptions (if there’s more than one in the log entry).

    You can also find the log as a text file in your Eclipse workspace directory, in .metadata/.log.

  • The Installation Details dialog can also give you some useful information. You find it by opening the About Eclipse box, then pressing Installation Details. In the Installed Software tab, you can check that Rascal is actually installed, and which version you have, and in the Configuration tab, you can check that your Java installation is OK.

Common Installation Problems

  • Eclipse starts but I can’t find the Rascal Perspective or any Rascal entries in the File → New menu

    This is typically because you’re running an old Java version instead of Java 8. Rascal requires the Java 8 SDK to run. You can check which Java you’re using by checking the java.version and entries in Installation Details → Configuration.

    If you’re running an old Java version even when Java 8 is installed, the simplest approach is just to remove all old installations of Java. You can also supply the path to the Java VM using the -vm option in your eclipse.ini file.

  • Eclipse starts, but I get an error message say that I need the Java JDK

    Install Java 8 JDK. If you have it installed but still get the error message, the simplest approach is just to remove all your installations of Java JRE (typically called just Java 8uXX on Windows). Your JDK installation will supply all functionality of the JRE. You can also supply the path to the correct Java VM using the -vm option in your eclipse.ini file.

  • Something goes wrong, and the exception in the Error Log says: “org.rascalmpl.interpreter.asserts.ImplementationError: Unexpected error in Rascal interpreter: Could not find an installed System Java Compiler, please provide a Java Runtime that includes the Java Development Tools”

    This is the same as the previous problem.

  • Rascal used to work, but I updated it and now it doesn’t

    Some requirements have changed in the stable release; you now need Java 8, and Eclipse Neon.3.

  • I use git, and it keeps hanging or using 100% CPU

    Install the most recent version of EGit from; the one bundled with Eclipse is buggy.

  • Installation complains about a missing “jetty” package

    Most likely you’re using an outdated version of Eclipse. Use Neon.3 or Oxygen instead.

  • I’m trying to install Rascal into Eclipse, but Eclipse can’t find the update site, or I’m trying to install Rascal into Eclipse, but the update site’s certificate can’t be validated.

    Our update site uses a Let’s Encrypt certificate, which has been supported by Java 8 since update 101. Most likely, you’re using an older Java version. Update to a recent Java 8 version. Alternatively, manually install Let’s Encrypt’s intermediate certificate to your truststore.