Configuring Scala compiler in IntelliJ 10.5? - scala

Question

I'm trying to get Scala working correctly in IntelliJ 10.5.1. I installed the plugin from the "available plugins" settings and then tried starting a new Java project, selecting "scala" under available technologies. But when I try running it, Scala says I haven't defined a scala compiler in the scala facet. So I went there, but I don't see any way of setting up the compiler. Also, my .iml file in my project looks like this:
<?xml version="1.0" encoding="UTF-8"?>
<module type="JAVA_MODULE" version="4">
<component name="FacetManager">
<facet type="scala" name="Scala">
<configuration>
<option name="compilerLibraryLevel" value="Global" />
<option name="pluginPaths">
<array>
<option value="$USER_HOME$/SDKs/scala/src/scala-compiler-src.jar" />
</array>
</option>
</configuration>
</facet>
</component>
<component name="NewModuleRootManager" inherit-compiler-output="true">
<exclude-output />
<content url="file://$MODULE_DIR$">
<sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
</content>
<orderEntry type="inheritedJdk" />
<orderEntry type="sourceFolder" forTests="false" />
<orderEntry type="library" name="scala " level="application" />
</component>
</module>
Notice that it does seem to be pointing to the correct jar compiler destination.
What do I need to do?
EDIT -
Compiler working now, but when I run, i get this error:
/System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home/bin/java -Didea.launcher.port=7540 -Didea.launcher.bin.path=/Applications/IntelliJ IDEA 10 CE.app/bin -Dfile.encoding=UTF-8 -classpath /System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home/lib/deploy.jar:/System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home/lib/dt.jar:/System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home/lib/javaws.jar:/System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home/lib/jce.jar:/System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home/lib/jconsole.jar:/System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home/lib/management-agent.jar:/System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home/lib/plugin.jar:/System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home/lib/sa-jdi.jar:/System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home/../Classes/alt-rt.jar:/System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home/../Classes/alt-string.jar:/System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home/../Classes/charsets.jar:/System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home/../Classes/classes.jar:/System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home/../Classes/jsse.jar:/System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home/../Classes/ui.jar:/System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home/lib/ext/apple_provider.jar:/System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home/lib/ext/dnsns.jar:/System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home/lib/ext/localedata.jar:/System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home/lib/ext/sunjce_provider.jar:/System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home/lib/ext/sunpkcs11.jar:/System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home:/Users/me/Projects/Scala/testing/out/test/testing:/Users/me/Projects/Scala/testing/out/production/testing:/Users/me/SDKs/scala/lib/scala-library.jar:/Users/me/SDKs/scala/lib/scala-swing.jar:/Users/me/SDKs/scala/lib/scala-dbc.jar:/Applications/IntelliJ IDEA 10 CE.app/lib/idea_rt.jar com.intellij.rt.execution.application.AppMain hello_world
Exception in thread "main" java.lang.ClassNotFoundException: hello_world
at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:169)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:113)
Process finished with exit code 1

Answer 1

Go to project settings (that could be invoked by Ctrl+Alt+Shift+S) and choose scala-compiler in libraries list just like that:
Now FacetManager component looks like this:
<component name="FacetManager">
<facet type="scala" name="Scala">
<configuration>
<option name="compilerLibraryLevel" value="Global" />
<option name="compilerLibraryName" value="scala-compiler-2.9.0.1" />
</configuration>
</facet>
</component>

Answer 2

See the Project Configuration Guide.
If you use SBT to build, I recommend using sbt-idea to generate your IDEA project, and idea-sbt-plugin to delegate project compilation within IDEA to SBT.

Answer 3

I guess you need to add the scala compiler library to the global libraries. In the module settings-> Global Libraries -> attach jar directories and select the lib folder under scala installation directory and then do as om-nom-nom suggested to make sure the compiler is selected.