Stack trace

IO error scanning directory '/var/lib/jenkins/jobs/Coverage_HEAD/workspace/coverage-qa'
	at org.apache.tools.ant.DirectoryScanner.scandir(DirectoryScanner.java:1207)
	at org.apache.tools.ant.DirectoryScanner.scandir(DirectoryScanner.java:1173)
	at org.apache.tools.ant.DirectoryScanner.checkIncludePatterns(DirectoryScanner.java:955)
	at org.apache.tools.ant.DirectoryScanner.scan(DirectoryScanner.java:909)
	at org.apache.tools.ant.types.AbstractFileSet.getDirectoryScanner(AbstractFileSet.java:499)
	at hudson.util.DirScanner$Glob.scan(DirScanner.java:128)
	at jenkins.util.VirtualFile$Scanner.invoke(VirtualFile.java:340)
	at jenkins.util.VirtualFile$Scanner.invoke(VirtualFile.java:333)
	at hudson.FilePath.act(FilePath.java:912)
	at hudson.FilePath.act(FilePath.java:885)
	at jenkins.util.VirtualFile$2.list(VirtualFile.java:299)
	at hudson.model.DirectoryBrowserSupport.zip(DirectoryBrowserSupport.java:343)
	at hudson.model.DirectoryBrowserSupport.serveFile(DirectoryBrowserSupport.java:216)
	at hudson.model.DirectoryBrowserSupport.generateResponse(DirectoryBrowserSupport.java:123)
	at org.kohsuke.stapler.HttpResponseRenderer$Default.handleHttpResponse(HttpResponseRenderer.java:110)
	at org.kohsuke.stapler.HttpResponseRenderer$Default.generateResponse(HttpResponseRenderer.java:64)
	at org.kohsuke.stapler.Function.renderResponse(Function.java:112)
	at org.kohsuke.stapler.Function.bindAndInvokeAndServeResponse(Function.java:97)
	at org.kohsuke.stapler.MetaClass$1.doDispatch(MetaClass.java:120)
	at org.kohsuke.stapler.NameBasedDispatcher.dispatch(NameBasedDispatcher.java:53)
	at org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:727)
	at org.kohsuke.stapler.Stapler.invoke(Stapler.java:841)
	at org.kohsuke.stapler.MetaClass$6.doDispatch(MetaClass.java:248)
	at org.kohsuke.stapler.NameBasedDispatcher.dispatch(NameBasedDispatcher.java:53)
	at org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:727)
	at org.kohsuke.stapler.Stapler.invoke(Stapler.java:841)
	at org.kohsuke.stapler.MetaClass$6.doDispatch(MetaClass.java:248)
	at org.kohsuke.stapler.NameBasedDispatcher.dispatch(NameBasedDispatcher.java:53)
	at org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:727)
	at org.kohsuke.stapler.Stapler.invoke(Stapler.java:841)
	at org.kohsuke.stapler.Stapler.invoke(Stapler.java:630)
	at org.kohsuke.stapler.Stapler.service(Stapler.java:224)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:848)
	at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:686)
	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1494)
	at hudson.util.PluginServletFilter$1.doFilter(PluginServletFilter.java:96)
	at hudson.util.PluginServletFilter.doFilter(PluginServletFilter.java:88)
	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1482)
	at hudson.security.csrf.CrumbFilter.doFilter(CrumbFilter.java:48)
	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1482)
	at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:84)
	at hudson.security.UnwrapSecurityExceptionFilter.doFilter(UnwrapSecurityExceptionFilter.java:51)
	at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
	at jenkins.security.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:117)
	at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
	at org.acegisecurity.providers.anonymous.AnonymousProcessingFilter.doFilter(AnonymousProcessingFilter.java:125)
	at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
	at org.acegisecurity.ui.rememberme.RememberMeProcessingFilter.doFilter(RememberMeProcessingFilter.java:142)
	at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
	at org.acegisecurity.ui.AbstractProcessingFilter.doFilter(AbstractProcessingFilter.java:271)
	at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
	at org.acegisecurity.ui.basicauth.BasicProcessingFilter.doFilter(BasicProcessingFilter.java:174)
	at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
	at jenkins.security.ApiTokenFilter.doFilter(ApiTokenFilter.java:64)
	at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
	at org.acegisecurity.context.HttpSessionContextIntegrationFilter.doFilter(HttpSessionContextIntegrationFilter.java:249)
	at hudson.security.HttpSessionContextIntegrationFilter2.doFilter(HttpSessionContextIntegrationFilter2.java:67)
	at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
	at hudson.security.ChainedServletFilter.doFilter(ChainedServletFilter.java:76)
	at hudson.security.HudsonFilter.doFilter(HudsonFilter.java:164)
	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1482)
	at org.kohsuke.stapler.compression.CompressionFilter.doFilter(CompressionFilter.java:46)
	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1482)
	at hudson.util.CharacterEncodingFilter.doFilter(CharacterEncodingFilter.java:81)
	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1474)
	at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:499)
	at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:137)
	at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:533)
	at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:231)
	at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1086)
	at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:428)
	at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:193)
	at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1020)
	at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:135)
	at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:116)
	at org.eclipse.jetty.server.Server.handle(Server.java:370)
	at org.eclipse.jetty.server.AbstractHttpConnection.handleRequest(AbstractHttpConnection.java:489)
	at org.eclipse.jetty.server.AbstractHttpConnection.headerComplete(AbstractHttpConnection.java:949)
	at org.eclipse.jetty.server.AbstractHttpConnection$RequestHandler.headerComplete(AbstractHttpConnection.java:1011)
	at org.eclipse.jetty.http.HttpParser.parseNext(HttpParser.java:644)
	at org.eclipse.jetty.http.HttpParser.parseAvailable(HttpParser.java:235)
	at org.eclipse.jetty.server.AsyncHttpConnection.handle(AsyncHttpConnection.java:82)
	at org.eclipse.jetty.io.nio.SelectChannelEndPoint.handle(SelectChannelEndPoint.java:668)
	at org.eclipse.jetty.io.nio.SelectChannelEndPoint$1.run(SelectChannelEndPoint.java:52)
	at winstone.BoundedExecutorService$1.run(BoundedExecutorService.java:77)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
	at java.lang.Thread.run(Thread.java:724)