With the current version of ruby metrics, it does not properly parse the output
from rcov 0.8.1.2 (at least for my projects). The summary chart on the main
build page is a broken image and the report detail page shows no values for line
counts or coverage percentages.

I get many stacktraces like this one in hudson/log:

Sep 24, 2008 9:44:32 PM hudson.ExpressionFactory2$JexlExpression evaluate
WARNING: Caught exception evaluating: it.results.totalCoveredWidth. Reason:
java.lang.reflect.InvocationTargetException
java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at org.apache.commons.jexl.util.PropertyExecutor.execute(PropertyExecutor.java:125)
at
org.apache.commons.jexl.util.introspection.UberspectImpl$VelGetterImpl.invoke(UberspectImpl.java:315)
at
org.apache.commons.jexl.parser.ASTArrayAccess.evaluateExpr(ASTArrayAccess.java:185)
at org.apache.commons.jexl.parser.ASTIdentifier.execute(ASTIdentifier.java:74)
at org.apache.commons.jexl.parser.ASTReference.execute(ASTReference.java:83)
at org.apache.commons.jexl.parser.ASTReference.value(ASTReference.java:57)
at
org.apache.commons.jexl.parser.ASTReferenceExpression.value(ASTReferenceExpression.java:51)
at org.apache.commons.jexl.ExpressionImpl.evaluate(ExpressionImpl.java:80)
at hudson.ExpressionFactory2$JexlExpression.evaluate(ExpressionFactory2.java:71)
at
org.apache.commons.jelly.expression.ExpressionSupport.evaluateRecurse(ExpressionSupport.java:61)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:232)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.TagSupport.invokeBody(TagSupport.java:186)
at org.apache.commons.jelly.impl.StaticTag.doTag(StaticTag.java:65)
at org.apache.commons.jelly.impl.StaticTagScript.run(StaticTagScript.java:112)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.TagSupport.invokeBody(TagSupport.java:186)
at org.apache.commons.jelly.impl.StaticTag.doTag(StaticTag.java:65)
at org.apache.commons.jelly.impl.StaticTagScript.run(StaticTagScript.java:112)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.TagSupport.invokeBody(TagSupport.java:186)
at org.apache.commons.jelly.impl.StaticTag.doTag(StaticTag.java:65)
at org.apache.commons.jelly.impl.StaticTagScript.run(StaticTagScript.java:112)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.tags.define.InvokeBodyTag.doTag(InvokeBodyTag.java:91)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:262)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.TagSupport.invokeBody(TagSupport.java:186)
at org.apache.commons.jelly.tags.core.IfTag.doTag(IfTag.java:42)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:262)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.TagSupport.invokeBody(TagSupport.java:186)
at org.apache.commons.jelly.tags.core.JellyTag.doTag(JellyTag.java:45)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:262)
at org.apache.commons.jelly.impl.DynamicTag.doTag(DynamicTag.java:80)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:262)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.tags.define.InvokeBodyTag.doTag(InvokeBodyTag.java:91)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:262)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.TagSupport.invokeBody(TagSupport.java:186)
at org.apache.commons.jelly.impl.StaticTag.doTag(StaticTag.java:65)
at org.apache.commons.jelly.impl.StaticTagScript.run(StaticTagScript.java:112)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.TagSupport.invokeBody(TagSupport.java:186)
at org.apache.commons.jelly.impl.StaticTag.doTag(StaticTag.java:65)
at org.apache.commons.jelly.impl.StaticTagScript.run(StaticTagScript.java:112)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.TagSupport.invokeBody(TagSupport.java:186)
at org.apache.commons.jelly.impl.StaticTag.doTag(StaticTag.java:65)
at org.apache.commons.jelly.impl.StaticTagScript.run(StaticTagScript.java:112)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.TagSupport.invokeBody(TagSupport.java:186)
at org.apache.commons.jelly.impl.StaticTag.doTag(StaticTag.java:65)
at org.apache.commons.jelly.impl.StaticTagScript.run(StaticTagScript.java:112)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.TagSupport.invokeBody(TagSupport.java:186)
at org.apache.commons.jelly.impl.StaticTag.doTag(StaticTag.java:65)
at org.apache.commons.jelly.impl.StaticTagScript.run(StaticTagScript.java:112)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.TagSupport.invokeBody(TagSupport.java:186)
at org.apache.commons.jelly.tags.core.JellyTag.doTag(JellyTag.java:45)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:262)
at org.apache.commons.jelly.impl.DynamicTag.doTag(DynamicTag.java:80)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:262)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.TagSupport.invokeBody(TagSupport.java:186)
at org.apache.commons.jelly.tags.core.JellyTag.doTag(JellyTag.java:45)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:262)
at
org.kohsuke.stapler.jelly.DefaultScriptInvoker.invokeScript(DefaultScriptInvoker.java:29)
at
org.kohsuke.stapler.jelly.JellyClassTearOff.serveIndexJelly(JellyClassTearOff.java:42)
at org.kohsuke.stapler.jelly.JellyFacet.handleIndexRequest(JellyFacet.java:67)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:398)
at org.kohsuke.stapler.MetaClass$12.dispatch(MetaClass.java:294)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:409)
at org.kohsuke.stapler.MetaClass$12.dispatch(MetaClass.java:294)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:409)
at org.kohsuke.stapler.MetaClass$6.doDispatch(MetaClass.java:173)
at org.kohsuke.stapler.NameBasedDispatcher.dispatch(NameBasedDispatcher.java:30)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:409)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:352)
at org.kohsuke.stapler.Stapler.service(Stapler.java:112)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at hudson.util.PluginServletFilter$1.doFilter(PluginServletFilter.java:61)
at hudson.util.PluginServletFilter.doFilter(PluginServletFilter.java:53)
at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:52)
at
hudson.security.UnwrapSecurityExceptionFilter.doFilter(UnwrapSecurityExceptionFilter.java:28)
at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:55)
at
org.acegisecurity.ui.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:166)
at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:55)
at
org.acegisecurity.providers.anonymous.AnonymousProcessingFilter.doFilter(AnonymousProcessingFilter.java:125)
at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:55)
at
hudson.security.BasicAuthenticationFilter.doFilter(BasicAuthenticationFilter.java:89)
at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:55)
at hudson.security.ChainedServletFilter.doFilter(ChainedServletFilter.java:44)
at hudson.security.HudsonFilter.doFilter(HudsonFilter.java:82)
at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at
org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:228)
at
org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
at
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:433)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)
at
org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:216)
at org.apache.jk.server.JkCoyoteHandler.invoke(JkCoyoteHandler.java:190)
at org.apache.jk.common.HandlerRequest.invoke(HandlerRequest.java:283)
at org.apache.jk.common.ChannelSocket.invoke(ChannelSocket.java:767)
at org.apache.jk.common.ChannelSocket.processConnection(ChannelSocket.java:697)
at
org.apache.jk.common.ChannelSocket$SocketConnection.runIt(ChannelSocket.java:889)
at
org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:686)
at java.lang.Thread.run(Thread.java:613)
Caused by: java.lang.NumberFormatException: empty String
at sun.misc.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:994)
at java.lang.Float.valueOf(Float.java:360)
at
hudson.plugins.rubyMetrics.rcov.model.RcovAbstractResult.getTotalCoverageFloat(RcovAbstractResult.java:35)
at
hudson.plugins.rubyMetrics.rcov.model.RcovAbstractResult.getTotalCoveredWidth(RcovAbstractResult.java:57)
... 120 more