Error in Eclipse with Scala IDE autocomplete

Question

Auto-complete (ctrl-space) fails in Eclipse with Scala IDE with the following error:

An internal error occurred during: "Computing additional info".
org.eclipse.jdt.internal.core.SearchableEnvironment.<init>
(Lorg/eclipse/jdt/internal/core/JavaProject;
Lorg/eclipse/jdt/core/WorkingCopyOwner;)V

How can I fix this?

Eclipse Version: 2018-12 (4.10.0)

Scala IDE version: 4.7.0 with Scala up to 2.12 installed

Answer 1

OK turns out this is a silly oversight on my part.

There was a breaking change in the constructor for SearchableEnvironment, where an additional argument was added. The latest Scala IDE is based on Eclipse 4.7 (Oxygen), and will not work with 4.10 / 2018-12 because of this.

Running Scala IDE with Eclipse 4.7 works now.