How to resolve Scala IDE / Maven errors: There was an error initializing the Scala compiler: could not find a required class: object scala.runtime in compiler mirror scala.reflect.internal.MissingRequirementError: object scala.runtime in compiler mirror not found.

compiler_mirror_error

I came across this problem while trying to add the Datastax Cassandra driver 
as a Maven dependency to a Scala project.

After adding the dependency to the pom, Scala IDE (3.0.1) complains with this 
error yes/no confirmation box.

Add Scala library to project classpath? There was an error initializing the 
Scala compiler: could not find a required class: object scala.runtime in 
compiler mirror. No/Yes

My life is a constant battle of mistrust with IDE environments, so when in 
doubt head for the command line:

mvn clean install 

produced a failed build with the same error:

error: error while loading <root>, error in opening zip file [ERROR] error: 
scala.reflect.internal.MissingRequirementError: object scala.runtime in 
compiler mirror not found.

Initially I thought the problem was with either the Datastax dependency or
 Scala/Scala IDE, but after a bit of googling 
(ref: https://groups.google.com/forum/#!msg/scala-user/A-aejw44XGs/QomJ5_Chd0sJ), 
it turns out its not directly related to either of them. The problem is actually
a corrupt jar somewhere in the Maven repository.

The solution:

1. The quickest and most invasive solution is empty your Maven repository 
and rebuild, to have it download everything fresh.

2. For a bit more precision, particularly if you have a large Maven repo,
 run 
	mvn dependency:tree 

on the project you're adding the new dependency to. Then pick out the
 transitive dependencies and only remove these from your repository.
 Rebuild your project and Maven should sort itself out.


mvn dependency:tree

tony@tony-pc:~/git-projects/snippets/parser-3gpp$ mvn dependency:tree
[INFO] Scanning for projects...
[INFO]                                                                         
[INFO] ------------------------------------------------------------------------
[INFO] Building parser-3gpp 0.0.1-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO] 
[INFO] --- maven-dependency-plugin:2.1:tree (default-cli) @ parser-3gpp ---
[INFO] com.clearprecision:parser-3gpp:jar:0.0.1-SNAPSHOT
[INFO] +- com.clearprecision:parser-api:jar:0.0.1-SNAPSHOT:compile
[INFO] +- com.datastax.cassandra:cassandra-driver-core:jar:1.0.0:compile
[INFO] |  +- io.netty:netty:jar:3.6.3.Final:compile
[INFO] |  +- com.google.guava:guava:jar:14.0.1:compile
[INFO] |  +- org.apache.cassandra:cassandra-thrift:jar:1.2.3:compile
[INFO] |  |  +- commons-lang:commons-lang:jar:2.4:compile
[INFO] |  |  \- org.slf4j:slf4j-api:jar:1.7.5:compile (version managed from 1.7.2)
[INFO] |  +- org.apache.thrift:libthrift:jar:0.7.0:compile
[INFO] |  |  +- javax.servlet:servlet-api:jar:2.5:compile
[INFO] |  |  \- org.apache.httpcomponents:httpclient:jar:4.0.1:compile
[INFO] |  |     +- org.apache.httpcomponents:httpcore:jar:4.0.1:compile
[INFO] |  |     \- commons-logging:commons-logging:jar:1.1.1:compile
[INFO] |  +- org.codehaus.jackson:jackson-core-asl:jar:1.9.2:compile
[INFO] |  +- com.yammer.metrics:metrics-core:jar:2.2.0:compile
[INFO] |  \- org.apache.cassandra:cassandra-all:jar:1.2.3:compile
[INFO] |     +- org.xerial.snappy:snappy-java:jar:1.0.4.1:compile
[INFO] |     +- net.jpountz.lz4:lz4:jar:1.1.0:compile
[INFO] |     +- com.ning:compress-lzf:jar:0.8.4:compile
[INFO] |     +- commons-cli:commons-cli:jar:1.1:compile
[INFO] |     +- commons-codec:commons-codec:jar:1.2:compile
[INFO] |     +- com.googlecode.concurrentlinkedhashmap:concurrentlinkedhashmap-lru:jar:1.3:compile
[INFO] |     +- org.antlr:antlr:jar:3.2:compile
[INFO] |     |  \- org.antlr:antlr-runtime:jar:3.2:compile
[INFO] |     |     \- org.antlr:stringtemplate:jar:3.2:compile
[INFO] |     |        \- antlr:antlr:jar:2.7.7:compile
[INFO] |     +- org.apache.cassandra.deps:avro:jar:1.4.0-cassandra-1:compile
[INFO] |     |  \- org.mortbay.jetty:jetty:jar:6.1.22:compile
[INFO] |     |     +- org.mortbay.jetty:jetty-util:jar:6.1.22:compile
[INFO] |     |     \- org.mortbay.jetty:servlet-api:jar:2.5-20081211:compile
[INFO] |     +- org.codehaus.jackson:jackson-mapper-asl:jar:1.9.2:compile
[INFO] |     +- jline:jline:jar:1.0:compile
[INFO] |     +- com.googlecode.json-simple:json-simple:jar:1.1:compile
[INFO] |     +- com.github.stephenc.high-scale-lib:high-scale-lib:jar:1.1.2:compile
[INFO] |     +- org.yaml:snakeyaml:jar:1.6:compile
[INFO] |     +- edu.stanford.ppl:snaptree:jar:0.1:compile
[INFO] |     +- org.mindrot:jbcrypt:jar:0.3m:compile
[INFO] |     +- log4j:log4j:jar:1.2.16:compile
[INFO] |     +- org.slf4j:slf4j-log4j12:jar:1.7.2:runtime
[INFO] |     \- com.github.stephenc:jamm:jar:0.2.5:compile
[INFO] +- org.scala-lang:scala-library:jar:2.10.2:compile
[INFO] +- junit:junit:jar:4.10:test
[INFO] |  \- org.hamcrest:hamcrest-core:jar:1.1:test
[INFO] +- com.typesafe.akka:akka-actor_2.10:jar:2.2.1:compile
[INFO] |  \- com.typesafe:config:jar:1.0.2:compile
[INFO] +- com.typesafe.akka:akka-testkit_2.10:jar:2.2.1:test
[INFO] \- org.scalatest:scalatest_2.10:jar:1.9.1:test
[INFO]    +- org.scala-lang:scala-actors:jar:2.10.0:test
[INFO]    \- org.scala-lang:scala-reflect:jar:2.10.0:test
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 13.796s
[INFO] Finished at: Thu Sep 19 13:10:00 IST 2013
[INFO] Final Memory: 11M/159M
[INFO] ------------------------------------------------------------------------


cd ~/.m2/repository

tony@tony-pc:~/.m2/repository$ rm -rf com/datastax/cassandra/cassandra-driver-core
tony@tony-pc:~/.m2/repository$ rm -rf io/netty/netty
tony@tony-pc:~/.m2/repository$ rm -rf com/google/guava/guava
tony@tony-pc:~/.m2/repository$ rm -rf org/apache/cassandra/cassandra-thrift
tony@tony-pc:~/.m2/repository$ rm -rf commons-lang/commons-lang
tony@tony-pc:~/.m2/repository$ rm -rf org/slf4j/slf4j-api
tony@tony-pc:~/.m2/repository$ rm -rf org/apache/thrift/libthrift
tony@tony-pc:~/.m2/repository$ rm -rf javax/servlet/servlet-api
tony@tony-pc:~/.m2/repository$ rm -rf org/apache/httpcomponents/httpclient
tony@tony-pc:~/.m2/repository$ rm -rf org/apache/httpcomponents/httpcore
tony@tony-pc:~/.m2/repository$ rm -rf commons-logging/commons-logging
tony@tony-pc:~/.m2/repository$ rm -rf org/codehaus/jackson/jackson-core-asl
tony@tony-pc:~/.m2/repository$ rm -rf com/yammer/metrics/metrics-core
tony@tony-pc:~/.m2/repository$ rm -rf org/apache/cassandra/cassandra-all
tony@tony-pc:~/.m2/repository$ rm -rf org/xerial/snappy/snappy-java
tony@tony-pc:~/.m2/repository$ rm -rf net/jpountz/lz4/lz4
tony@tony-pc:~/.m2/repository$ rm -rf com/ning/compress-lzf
tony@tony-pc:~/.m2/repository$ rm -rf commons-cli/commons-cli
tony@tony-pc:~/.m2/repository$ rm -rf commons-codec/commons-codec
tony@tony-pc:~/.m2/repository$ rm -rf com/googlecode/concurrentlinkedhashmap/concurrentlinkedhashmap-lru
tony@tony-pc:~/.m2/repository$ rm -rf org/antlr/antlr
tony@tony-pc:~/.m2/repository$ rm -rf org/antlr/antlr-runtime
tony@tony-pc:~/.m2/repository$ rm -rf org/antlr/stringtemplate
tony@tony-pc:~/.m2/repository$ rm -rf antlr/antlr
tony@tony-pc:~/.m2/repository$ rm -rf org/apache/cassandra/deps/avro
tony@tony-pc:~/.m2/repository$ rm -rf org/mortbay/jetty/jetty
tony@tony-pc:~/.m2/repository$ rm -rf org/mortbay/jetty/jetty-util
tony@tony-pc:~/.m2/repository$ rm -rf org/mortbay/jetty/servlet-api
tony@tony-pc:~/.m2/repository$ rm -rf org/codehaus/jackson/jackson-mapper-asl
tony@tony-pc:~/.m2/repository$ rm -rf jline/jline
tony@tony-pc:~/.m2/repository$ rm -rf com/googlecode/json-simple/json-simple
tony@tony-pc:~/.m2/repository$ rm -rf com/github/stephenc/high-scale-lib/high-scale-lib
tony@tony-pc:~/.m2/repository$ rm -rf org/yaml/snakeyaml
tony@tony-pc:~/.m2/repository$ rm -rf edu/stanford/ppl/snaptree
tony@tony-pc:~/.m2/repository$ rm -rf org/mindrot/jbcrypt
tony@tony-pc:~/.m2/repository$ rm -rf log4j/log4j
tony@tony-pc:~/.m2/repository$ rm -rf org/slf4j/slf4j-log4j12
tony@tony-pc:~/.m2/repository$ rm -rf com/github/stephenc/jamm

Hi, tjayr. I also meet a problem like yours. I also google the solution you mentioned. I also tried your first solution. But it didn't work. The scala.runtime error still existed. Do you know any other reasons how this problem occurs?