I suspect it’s in NaBL, because this is the last output in the spoofax console:

13:44 | INFO  | o.m.c.build.Builder            - Building 17 sources, 0 includes of language impl. org.metaborg:org.metaborg.meta.lang.template-1.5.0-SNAPSHOT
13:44 | INFO  | o.m.c.build.Builder            - Building 6 sources, 0 includes of language impl. org.metaborg:org.metaborg.meta.lang.nabl-1.5.0-SNAPSHOT
13:44 | INFO  | o.m.c.build.Builder            - Building 19 sources, 0 includes of language impl. org.metaborg:org.metaborg.meta.lang.ts-1.5.0-SNAPSHOT
13:44 | INFO  | o.m.c.build.Builder            - Building 16 sources, 0 includes of language impl. org.metaborg:org.metaborg.meta.lang.esv-1.5.0-SNAPSHOT
13:44 | INFO  | o.m.c.build.Builder            - Building 17 sources, 0 includes of language impl. org.metaborg:org.metaborg.meta.lang.template-1.5.0-SNAPSHOT
13:44 | INFO  | o.m.c.build.Builder            - Building 6 sources, 0 includes of language impl. org.metaborg:org.metaborg.meta.lang.nabl-1.5.0-SNAPSHOT

The stacktrace from the error log is:

java.lang.ClassCastException: org.spoofax.terms.StrategoList cannot be cast to org.spoofax.interpreter.terms.IStrategoString
	at org.metaborg.spoofax.core.analysis.StrategoAnalysisService.makeMessages(StrategoAnalysisService.java:394)
	at org.metaborg.spoofax.core.analysis.StrategoAnalysisService.multiASTMakeResult(StrategoAnalysisService.java:346)
	at org.metaborg.spoofax.core.analysis.StrategoAnalysisService.analyzeMultiAST(StrategoAnalysisService.java:322)
	at org.metaborg.spoofax.core.analysis.StrategoAnalysisService.analyze(StrategoAnalysisService.java:114)
	at org.metaborg.core.build.Builder.analyze(Builder.java:331)
	at org.metaborg.core.build.Builder.updateLanguageResources(Builder.java:231)
	at org.metaborg.core.build.Builder.build(Builder.java:169)
	at org.metaborg.spoofax.eclipse.build.BuildRunnable.run(BuildRunnable.java:59)
	at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:2313)
	at org.metaborg.spoofax.eclipse.processing.RunnableTask.schedule(RunnableTask.java:41)
	at org.metaborg.spoofax.eclipse.build.SpoofaxProjectBuilder.build(SpoofaxProjectBuilder.java:100)
	at org.eclipse.core.internal.events.BuildManager$2.run(BuildManager.java:734)
	at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
	at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:206)
	at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:246)
	at org.eclipse.core.internal.events.BuildManager$1.run(BuildManager.java:299)
	at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
	at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:302)
	at org.eclipse.core.internal.events.BuildManager.basicBuildLoop(BuildManager.java:358)
	at org.eclipse.core.internal.events.BuildManager.build(BuildManager.java:381)
	at org.eclipse.core.internal.events.AutoBuildJob.doBuild(AutoBuildJob.java:143)
	at org.eclipse.core.internal.events.AutoBuildJob.run(AutoBuildJob.java:241)
	at org.eclipse.core.internal.jobs.Worker.run(Worker.java:54)

---

Eclipse: org.eclipse.epp.package.standard.feature.feature.group 4.4.2.20150219-0708
Spoofax: org.metaborg.spoofax.eclipse 1.5.0.20150915-022547-new-spoofax-plugin
System: Linux amd64 3.13.0-37-generic

Submitted by Jeff Smits on 15 September 2015 at 23:19

Fixed