I recently upgraded to the m1 mac. And am trying to set up my scala environment for a project. However, I'm getting this error when I'm trying to get my sbt to sync.
[error] [launcher] error during sbt launcher: java.lang.ClassCastException: class java.lang.UnsupportedOperationException cannot be cast to class xsbti.FullReload (java.lang.UnsupportedOperationException is in module java.base of loader 'bootstrap'; xsbti.FullReload is in unnamed module of loader 'app')
I was on corretto at first. But then I read somewhere and downloaded temurin via installing through sdk using
sdk install java
sdk install sbt
After installing it, I'm able to run sbt on the project in my terminal. However, within Intellij (even after changing the java sdk to temurin). I'm still getting that error.
The solution that I came upon to fix this was by using the right Java sdk. Using Corretto wasn't working, so I used sdkman to download java sdk instead. It downloaded Java Temurin, and i then changed to use Temurin. It worked after.
I'm having some problems getting my Scala tests running via the Intelli-J Run/Debug configuration. The tests are working if I run them directly in the SBT console.
My configuration looks like this:
I'm getting this error in the Run console panel:
java.lang.IllegalArgumentException: ERROR: -r has been deprecated for a very long time and is no longer supported, to prepare for reusing it for a different purpose in the near future. Please change all uses of -r to -C.
at org.scalatest.tools.ArgsParser$.checkArgsForValidity(ArgsParser.scala:41)
at org.scalatest.tools.Runner$.runOptionallyWithPassFailReporter(Runner.scala:857)
at org.scalatest.tools.Runner$.run(Runner.scala:850)
at org.scalatest.tools.Runner.run(Runner.scala)
at org.jetbrains.plugins.scala.testingSupport.scalaTest.ScalaTestRunner.runScalaTest2(ScalaTestRunner.java:141)
at org.jetbrains.plugins.scala.testingSupport.scalaTest.ScalaTestRunner.main(ScalaTestRunner.java:32)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:134)
I've checked my plugins are all up-to-date. Do I need to use a particular version of Scala? Or is there some additional setup I'm missing?
For anyone who has this problem even with newer version of IntelliJ, here is how I went about figuring out where the issue was. I pulled in the scalatest dependency at the top of the pom for the module I was trying to run tests in. Then an individual test would run without this error. I moved the dependency down the pom until the problem recurred to figure out which dependency was causing the problem. Then I found that the dependency had some really old dependencies including an older version of scalatest that weren't showing up in my dependency tree. Also, this jar dependency had scalatest as a dependency not marked with scope test.
It appears to have been a problem with the Scala plugin under Intelli-J 13.
I fixed this by upgrading to Intelli-J 2016.3, which I presume has been changed to pass the newer -C switch to ScalaTestRunner.
#JasonF pointed out in his comment below that a project dependency can also cause a problem with the scalatest plugin (this was the case for him). It's worth attempting to run the tests of a fresh sample Scala project to test for this scenario before upgrading the IDE.
Sometimes when updating a dependency version for my project, when I would run the project I would get the following error:
ERROR 09:31:34:241 apply$mcV$sp - Class could not be loaded and/or registered: scala.Enumeration$Val
ERROR 09:31:34:247 apply$mcV$sp - exception caught during akka-kryo-serialization startup: java.lang.ClassNotFoundException: scala.Enumeration$Val
java.lang.RuntimeException: Nonzero exit code: 1
at scala.sys.package$.error(package.scala:27)
I usually got lucky and was able to fix this by tweaking the versions of my dependencies.
Until I updated my akka version from 2.3.6 to 2.3.12, specifically akka-contrib which contains akka-cluster, akka-remote and akka-peristance.
Turns out that the problem was actually occurring during the transition between akka 2.3.8 and 2.3.9. Looking at the change log, I found that between these two versions the Scala version was upgraded from 2.11.4 to 2.11.5.
My project was building on scala 2.11.4. Upgrading to 2.11.5 fixed the problem.
I couldn't find any help online for this, and lost a couple days trying to figure this out. I'm hoping that this will help someone else out.
In Eclipse Juno when I try to run Groovy source (that has a main method inside of it) I get:
Caught: java.lang.ExceptionInInitializerError
java.lang.ExceptionInInitializerError
Caused by: groovy.lang.GroovyRuntimeException: Conflicting module versions. Module [groovy-all is loaded in version 2.3.4 and you are trying to load version 2.3.3
Google, surprisingly, turned up nothing. When I go to Project >> Properties >> Groovy Compiler I see that my Groovy compiler is at 2.3, but it doesn't give me the option to select 2.3.3 or 2.3.4.
Any ideas what the fix is?
There is no fix for that. Each groovy-eclipse compiler is a version tweaked to work with eclipse JDT and whatnot. You can try to use other groovy-eclipse versions, which might feature the groovy version you need
I successfully implemented and ran several Scala tutorials in Eclipse using the Scala plugin. Then suddenly I tried to compile and run an example, and this error came up:
Exception in thread "main" java.lang.NoClassDefFoundError: hello/HelloWorld
Caused by: java.lang.ClassNotFoundException: hello.HelloWorld
at java.net.URLClassLoader$1.run(URLClassLoader.java:200)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
at java.lang.ClassLoader.loadClass(ClassLoader.java:315)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:330)
at java.lang.ClassLoader.loadClass(ClassLoader.java:250)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:398)
After this point I could no longer run any Scala programs in Eclipse. I tried cleaning and rebuilding my project, closing and reopening my project, and closing and reopening Eclipse.
Eclipse version number 3.5.2 and Scala plugin 2.8.0
Here is the original code:
package hello
object HelloWorld {
def main(args: Array[String]){
println("hello world")
}
}
If you see this when you attempt to run as a Scala application then the most likely explanation is that your project didn't compile and no class files were generated. Please check whether or not that's the case: look in your project's output folder for hello/HelloWorld.class.
If your project didn't compile that could either be because there's an error which you've missed (and if this error isn't being reported in the Problems view that could be a bug, in which case please open a ticket on Trac) or because you've turned off automatic builds and not done a manual build of your project.
I had the same problem. Project doesn't compile but there are no errors highlighted and AFAIK the code is OK. It seems to be a problem with the Run Configurations.
Solution 1: Delete the existing Run Configuration for your object and create a new one
Solution 2: Create a new object and cut / paste all your code into that file
When running "clean" does not un-hose Eclipse, I next try saving my work, exiting Eclipse, and re-starting. That usually gets things going again, but not always. A few times I've had to update the Scala plugin with a more recent version (I'm using the latest nightly), to get things working again. I doubt that this worked because the new plugin happened to fix the bug, but rather expect that loading the new plugin gives the whole Eclipse-Scala
system a "total reset" that gets it unhosed.
I was getting this problem in a project that combined .java & .scala files.
The solution for me was:
Remove all .java files
Edit the scala code as needed so it compiles without them.
Add the .java files back in.
Edit the scala code back.
The other solutions given here didn't work for me. I tried: clean project, restarting Eclipse, closing-&-opening the project, creating a new .scala file. No joy.
I'm using Eclipse 3.7 (latest stable), Scala IDE 2.0.0 and Scala 2.9 on Ubuntu Linux 11.10.
The symptoms in my case were:
My project was working, but then it stopped compiling for no apparent reason. The IDE didn't show any compilation errors for .scala files, but there were no .class files in the output directory & I got a NoClassDefError if I tried to run anything.
If I created a deliberate error in a .scala file, that did get picked up as a compilation error.
The .java files were registering errors due to the missing scala classes.
I suppose there's probably a boot-strapping bug somewhere in the IDE plugin for .java/.scala mixes. I've done hybrid projects with this setup without problems, so it's only triggered in some situations. I don't know what the trigger is, but once triggered, there's no nice solution.
I had moved my one and only class/object/application to a package, but had not added the package declaration.
sbt compiled and ran fine; eclipse would not
Adding the package declaration at the top of the file fixed it.
Scala 2.8.3 plugin; no compile error
I encountered this error too but after doing the suggestions here (cleaning, deleting Run Configuration etc), I realized that I set the workspace wrongly that is why the class is not being found.
An indication that this is a problem is when the same error occurs when you try to compile a java project.
I encountered this error (compilation worked in sbt but failed in eclipse) when I created a new package object called "common". Deleting the package object in eclipse caused the compile error to go away. There was nothing in it.
I was using sbt-eclipse to build the eclipse project. I'm using scala eclipse 3.0.0-vfinal-20130326-1146-Typesafe.