FULL PRODUCT VERSION :
java version "1.8.0_20"
Java(TM) SE Runtime Environment (build 1.8.0_20-b26)
Java HotSpot(TM) 64-Bit Server VM (build 25.20-b23, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
Linux augusto-Studio-1558 3.13.0-34-generic #60-Ubuntu SMP Wed Aug 13 15:45:27 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux

A DESCRIPTION OF THE PROBLEM :
When building with maven, either from intelij or command line, compilation fails with "java.lang.AssertionError: isSubClass TChild". Compilation does not fail with jdk 1.8u11.

REGRESSION. Last worked in version 8u11

ADDITIONAL REGRESSION INFORMATION:
java version "1.8.0_11"
Java(TM) SE Runtime Environment (build 1.8.0_11-b12)
Java HotSpot(TM) 64-Bit Server VM (build 25.11-b03, mixed mode)


STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
mvn compile

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
successful compilation
ACTUAL -
[ERROR] Failure executing javac, but could not parse the error:
An exception has occurred in the compiler (1.8.0_20). Please file a bug at the Java Developer Connection (http://java.sun.com/webapps/bugreport) after checking the Bug Parade for duplicates. Include your program and the following diagnostic in your report. Thank you.
java.lang.AssertionError: isSubClass TChild
at com.sun.tools.javac.code.Symbol.isSubClass(Symbol.java:447)
at com.sun.tools.javac.code.Symbol.isMemberOf(Symbol.java:456)
at com.sun.tools.javac.code.Symbol$MethodSymbol.overrides(Symbol.java:1469)
at com.sun.tools.javac.code.Types$ImplementationCache.implementationInternal(Types.java:2671)
at com.sun.tools.javac.code.Types$ImplementationCache.get(Types.java:2653)
at com.sun.tools.javac.code.Types.implementation(Types.java:2682)
at com.sun.tools.javac.code.Symbol$MethodSymbol.implementation(Symbol.java:1529)
at com.sun.tools.javac.code.Symbol$MethodSymbol.implementation(Symbol.java:1518)
at com.sun.tools.javac.comp.Resolve.notOverriddenIn(Resolve.java:416)
at com.sun.tools.javac.comp.Resolve.isAccessible(Resolve.java:402)
at com.sun.tools.javac.comp.Resolve.isAccessible(Resolve.java:362)
at com.sun.tools.javac.comp.Resolve.selectBest(Resolve.java:1448)
at com.sun.tools.javac.comp.Resolve.findMethodInScope(Resolve.java:1618)
at com.sun.tools.javac.comp.Resolve.findMethod(Resolve.java:1710)
at com.sun.tools.javac.comp.Resolve.findMethod(Resolve.java:1662)
at com.sun.tools.javac.comp.DeferredAttr$DeferredChecker$2.lookup(DeferredAttr.java:1325)
at com.sun.tools.javac.comp.Resolve.lookupMethod(Resolve.java:3325)
at com.sun.tools.javac.comp.Resolve.lookupMethod(Resolve.java:3310)
at com.sun.tools.javac.comp.DeferredAttr$DeferredChecker.quicklyResolveMethod(DeferredAttr.java:1333)
at com.sun.tools.javac.comp.DeferredAttr$DeferredChecker.visitApply(DeferredAttr.java:1223)
at com.sun.tools.javac.tree.JCTree$JCMethodInvocation.accept(JCTree.java:1465)
at com.sun.tools.javac.tree.TreeScanner.scan(TreeScanner.java:49)
at com.sun.tools.javac.comp.DeferredAttr$FilterScanner.scan(DeferredAttr.java:901)
at com.sun.tools.javac.comp.DeferredAttr.isDeferred(DeferredAttr.java:1088)
at com.sun.tools.javac.comp.Attr.attribArgs(Attr.java:701)
at com.sun.tools.javac.comp.Attr.visitApply(Attr.java:1834)
at com.sun.tools.javac.tree.JCTree$JCMethodInvocation.accept(JCTree.java:1465)
at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:607)
at com.sun.tools.javac.comp.Attr.attribExpr(Attr.java:656)
at com.sun.tools.javac.comp.Attr.visitExec(Attr.java:1611)
at com.sun.tools.javac.tree.JCTree$JCExpressionStatement.accept(JCTree.java:1296)
at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:607)
at com.sun.tools.javac.comp.Attr.attribStat(Attr.java:676)
at com.sun.tools.javac.comp.Attr.attribStats(Attr.java:692)
at com.sun.tools.javac.comp.Attr.visitBlock(Attr.java:1142)
at com.sun.tools.javac.tree.JCTree$JCBlock.accept(JCTree.java:909)
at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:607)
at com.sun.tools.javac.comp.Attr.attribStat(Attr.java:676)
at com.sun.tools.javac.comp.Attr.visitIf(Attr.java:1600)
at com.sun.tools.javac.tree.JCTree$JCIf.accept(JCTree.java:1269)
at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:607)
at com.sun.tools.javac.comp.Attr.attribStat(Attr.java:676)
at com.sun.tools.javac.comp.Attr.attribStats(Attr.java:692)
at com.sun.tools.javac.comp.Attr.visitBlock(Attr.java:1142)
at com.sun.tools.javac.tree.JCTree$JCBlock.accept(JCTree.java:909)
at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:607)
at com.sun.tools.javac.comp.Attr.attribStat(Attr.java:676)
at com.sun.tools.javac.comp.Attr.visitIf(Attr.java:1600)
at com.sun.tools.javac.tree.JCTree$JCIf.accept(JCTree.java:1269)
at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:607)
at com.sun.tools.javac.comp.Attr.attribStat(Attr.java:676)
at com.sun.tools.javac.comp.Attr.attribStats(Attr.java:692)
at com.sun.tools.javac.comp.Attr.visitBlock(Attr.java:1142)
at com.sun.tools.javac.tree.JCTree$JCBlock.accept(JCTree.java:909)
at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:607)
at com.sun.tools.javac.comp.Attr.attribStat(Attr.java:676)
at com.sun.tools.javac.comp.Attr.visitMethodDef(Attr.java:1035)
at com.sun.tools.javac.tree.JCTree$JCMethodDecl.accept(JCTree.java:778)
at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:607)
at com.sun.tools.javac.comp.Attr.attribStat(Attr.java:676)
at com.sun.tools.javac.comp.Attr.attribClassBody(Attr.java:4342)
at com.sun.tools.javac.comp.Attr.attribClass(Attr.java:4252)
at com.sun.tools.javac.comp.Attr.attribClass(Attr.java:4201)
at com.sun.tools.javac.comp.Attr.attribClass(Attr.java:4181)
at com.sun.tools.javac.comp.Attr.attrib(Attr.java:4156)
at com.sun.tools.javac.main.JavaCompiler.attribute(JavaCompiler.java:1248)
at com.sun.tools.javac.main.JavaCompiler.compile2(JavaCompiler.java:901)
at com.sun.tools.javac.main.JavaCompiler.compile(JavaCompiler.java:860)
at com.sun.tools.javac.main.Main.compile(Main.java:523)
at com.sun.tools.javac.main.Main.compile(Main.java:381)
at com.sun.tools.javac.main.Main.compile(Main.java:370)
at com.sun.tools.javac.main.Main.compile(Main.java:361)
at com.sun.tools.javac.Main.compile(Main.java:74)
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 org.codehaus.plexus.compiler.javac.JavacCompiler.compileInProcess0(JavacCompiler.java:551)
at org.codehaus.plexus.compiler.javac.JavacCompiler.compileInProcess(JavacCompiler.java:526)
at org.codehaus.plexus.compiler.javac.JavacCompiler.compile(JavacCompiler.java:167)
at org.apache.maven.plugin.AbstractCompilerMojo.execute(AbstractCompilerMojo.java:678)
at org.apache.maven.plugin.CompilerMojo.execute(CompilerMojo.java:128)
at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:133)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:208)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:108)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:76)
at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build(SingleThreadedBuilder.java:51)
at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:116)
at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:361)
at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:155)
at org.apache.maven.cli.MavenCli.execute(MavenCli.java:584)
at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:213)
at org.apache.maven.cli.MavenCli.main(MavenCli.java:157)
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 org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:289)
at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229)
at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415)
at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356)
at org.codehaus.classworlds.Launcher.main(Launcher.java:46)
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:120)

REPRODUCIBILITY :
This bug can be reproduced always.

CUSTOMER SUBMITTED WORKAROUND :
downgrade to 1.8u11