If you have a dodgy source jar file, it will probably blow up the ensime server with java.util.zip.ZipException: error in opening zip file. The solution offered in the project’s Github issue is to delete your local copy of the bad file and add it to the list of excluded classifiers in ivy (i.e. ~/.ivy2/exclude_classifiers), and report the file to the nexus hosts to have it deleted.

Mine is a bit longer …

I struggled with this error for weeks! In my case, the offending JAR was a transitive dependency of a project, and the solution offered here was not clear enough for me.

This problem is tricky if you previously loaded the project into an IDE: they download by default all transitive dependencies with sources and javadoc, and the ivy cache is shared by all projects in the same machine.

Here is my solution, in case it helps others:

• determine which dependency is pulling the problem JAR with the sbt dependency graph plugin (note: the command whatDependsOn only works in interactive mode)
• move away the current ivy cache folder console $ mv ~/.ivy2/ ~/.ivy2_old
• (optional) create a new clone to have a known state console $ git clone $repo ~/dev/ensime-$repo
• edit build.sbt to add an exclusion rule for the transitive dependency at the line of the explicit dependency that needs it, e.g. sbt libraryDependencies ++= Seq( "com.company.notifications" % "notifications-schema" exclude("org.json", "json") )
• compile, go for a coffee while ivy downloads the internet :smile:, then run ensime commands console $ sbt compile $ sbt ensimeConfig ensimeConfigProject