Although retry count in trigger step was set to 5, only first try did really trigger a build. According to log, it seems all others take cached result from first try:

Log
Step Log (master>execute>execute-sequential-dispatch-groups>execute-parallel-dispatch-targets?dispatchTargetsVarName=dispatchTargets>execute-trigger-build?configName=build)
Show Steps
09:43:06,645 INFO - Checking step execute condition...
09:43:06,645 INFO - Step execute condition satisfied, executing...
09:43:06,788 INFO - Executing pre-execute action...
09:43:06,788 INFO - Running step...
09:43:48,565 INFO - Executing post-execute action...
09:43:48,565 ERROR - Error executing step
    com.pmease.quickbuild.QuickbuildException: Can not resolve requested build for configuration 'root/build'. Check server log for details.
        at com.pmease.quickbuild.grid.NodeServiceImpl.getBuildId(NodeServiceImpl.java:258)
        at com.pmease.quickbuild.plugin.basis.TriggerBuildStep.run(TriggerBuildStep.java:276)
        at com.pmease.quickbuild.plugin.basis.TriggerBuildStep$$EnhancerByCGLIB$$63296bbe.CGLIB$run$13(<generated>)
        at com.pmease.quickbuild.plugin.basis.TriggerBuildStep$$EnhancerByCGLIB$$63296bbe$$FastClassByCGLIB$$d4683b63.invoke(<generated>)
        at net.sf.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:215)
        at com.pmease.quickbuild.DefaultScriptEngine$Interpolator.intercept(DefaultScriptEngine.java:261)
        at com.pmease.quickbuild.plugin.basis.TriggerBuildStep$$EnhancerByCGLIB$$63296bbe.run(<generated>)
        at com.pmease.quickbuild.stepsupport.Step.doExecute(Step.java:664)
        at com.pmease.quickbuild.stepsupport.Step.execute(Step.java:570)
        at com.pmease.quickbuild.stepsupport.StepExecutionJob.executeStepAwareJob(StepExecutionJob.java:31)
        at com.pmease.quickbuild.stepsupport.StepAwareJob.executeBuildAwareJob(StepAwareJob.java:56)
        at com.pmease.quickbuild.BuildAwareJob.execute(BuildAwareJob.java:77)
        at com.pmease.quickbuild.grid.GridJob.run(GridJob.java:129)
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
        at java.util.concurrent.FutureTask.run(FutureTask.java:266)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
        at java.lang.Thread.run(Thread.java:748)
09:45:48,565 INFO - Executing pre-execute action...
09:45:48,565 INFO - Running step...
09:45:48,878 INFO - Executing post-execute action...
09:45:48,878 ERROR - Error executing step
    com.pmease.quickbuild.RemotingException: Can not resolve requested build for configuration 'root/build'. Check server log for details.
        at com.pmease.quickbuild.DefaultBuildEngine.getBuildId(DefaultBuildEngine.java:2180)
        at com.pmease.quickbuild.ServerServiceImpl.getBuildId(ServerServiceImpl.java:268)
        at sun.reflect.GeneratedMethodAccessor514.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at com.caucho.hessian.server.HessianSkeleton.invoke(HessianSkeleton.java:302)
        at com.caucho.hessian.server.HessianSkeleton.invoke(HessianSkeleton.java:198)
        at com.caucho.hessian.server.HessianServlet.invoke(HessianServlet.java:399)
        at com.caucho.hessian.server.HessianServlet.service(HessianServlet.java:379)
        at com.pmease.quickbuild.grid.GridServlet.service(GridServlet.java:36)
        at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:812)
        at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1669)
        at com.pmease.quickbuild.Quickbuild$DisableTraceFilter.doFilter(Quickbuild.java:1139)
        at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1652)
        at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:585)
        at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:221)
        at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1127)
        at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:515)
        at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:185)
        at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1061)
        at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
        at org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:110)
        at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:97)
        at org.eclipse.jetty.server.Server.handle(Server.java:499)
        at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:311)
        at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:258)
        at org.eclipse.jetty.io.AbstractConnection$2.run(AbstractConnection.java:544)
        at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:635)
        at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:555)
        at java.lang.Thread.run(Thread.java:748)
09:47:48,878 INFO - Executing pre-execute action...
09:47:48,878 INFO - Running step...
09:47:49,142 INFO - Executing post-execute action...
09:47:49,142 ERROR - Error executing step
    com.pmease.quickbuild.RemotingException: Can not resolve requested build for configuration 'root/build'. Check server log for details.
        at com.pmease.quickbuild.DefaultBuildEngine.getBuildId(DefaultBuildEngine.java:2180)
        at com.pmease.quickbuild.ServerServiceImpl.getBuildId(ServerServiceImpl.java:268)
        at sun.reflect.GeneratedMethodAccessor514.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at com.caucho.hessian.server.HessianSkeleton.invoke(HessianSkeleton.java:302)
        at com.caucho.hessian.server.HessianSkeleton.invoke(HessianSkeleton.java:198)
        at com.caucho.hessian.server.HessianServlet.invoke(HessianServlet.java:399)
        at com.caucho.hessian.server.HessianServlet.service(HessianServlet.java:379)
        at com.pmease.quickbuild.grid.GridServlet.service(GridServlet.java:36)
        at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:812)
        at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1669)
        at com.pmease.quickbuild.Quickbuild$DisableTraceFilter.doFilter(Quickbuild.java:1139)
        at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1652)
        at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:585)
        at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:221)
        at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1127)
        at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:515)
        at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:185)
        at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1061)
        at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
        at org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:110)
        at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:97)
        at org.eclipse.jetty.server.Server.handle(Server.java:499)
        at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:311)
        at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:258)
        at org.eclipse.jetty.io.AbstractConnection$2.run(AbstractConnection.java:544)
        at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:635)
        at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:555)
        at java.lang.Thread.run(Thread.java:748)
09:49:49,142 INFO - Executing pre-execute action...
09:49:49,143 INFO - Running step...
09:49:49,443 INFO - Executing post-execute action...
09:49:49,443 ERROR - Error executing step
    com.pmease.quickbuild.RemotingException: Can not resolve requested build for configuration 'root/build'. Check server log for details.
        at com.pmease.quickbuild.DefaultBuildEngine.getBuildId(DefaultBuildEngine.java:2180)
        at com.pmease.quickbuild.ServerServiceImpl.getBuildId(ServerServiceImpl.java:268)
        at sun.reflect.GeneratedMethodAccessor514.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at com.caucho.hessian.server.HessianSkeleton.invoke(HessianSkeleton.java:302)
        at com.caucho.hessian.server.HessianSkeleton.invoke(HessianSkeleton.java:198)
        at com.caucho.hessian.server.HessianServlet.invoke(HessianServlet.java:399)
        at com.caucho.hessian.server.HessianServlet.service(HessianServlet.java:379)
        at com.pmease.quickbuild.grid.GridServlet.service(GridServlet.java:36)
        at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:812)
        at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1669)
        at com.pmease.quickbuild.Quickbuild$DisableTraceFilter.doFilter(Quickbuild.java:1139)
        at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1652)
        at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:585)
        at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:221)
        at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1127)
        at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:515)
        at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:185)
        at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1061)
        at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
        at org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:110)
        at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:97)
        at org.eclipse.jetty.server.Server.handle(Server.java:499)
        at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:311)
        at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:258)
        at org.eclipse.jetty.io.AbstractConnection$2.run(AbstractConnection.java:544)
        at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:635)
        at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:555)
        at java.lang.Thread.run(Thread.java:748)
09:51:49,443 INFO - Executing pre-execute action...
09:51:49,443 INFO - Running step...
09:51:49,775 INFO - Executing post-execute action...
09:51:49,775 ERROR - Error executing step
    com.pmease.quickbuild.RemotingException: Can not resolve requested build for configuration 'root/build'. Check server log for details.
        at com.pmease.quickbuild.DefaultBuildEngine.getBuildId(DefaultBuildEngine.java:2180)
        at com.pmease.quickbuild.ServerServiceImpl.getBuildId(ServerServiceImpl.java:268)
        at sun.reflect.GeneratedMethodAccessor514.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at com.caucho.hessian.server.HessianSkeleton.invoke(HessianSkeleton.java:302)
        at com.caucho.hessian.server.HessianSkeleton.invoke(HessianSkeleton.java:198)
        at com.caucho.hessian.server.HessianServlet.invoke(HessianServlet.java:399)
        at com.caucho.hessian.server.HessianServlet.service(HessianServlet.java:379)
        at com.pmease.quickbuild.grid.GridServlet.service(GridServlet.java:36)
        at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:812)
        at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1669)
        at com.pmease.quickbuild.Quickbuild$DisableTraceFilter.doFilter(Quickbuild.java:1139)
        at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1652)
        at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:585)
        at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:221)
        at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1127)
        at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:515)
        at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:185)
        at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1061)
        at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
        at org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:110)
        at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:97)
        at org.eclipse.jetty.server.Server.handle(Server.java:499)
        at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:311)
        at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:258)
        at org.eclipse.jetty.io.AbstractConnection$2.run(AbstractConnection.java:544)
        at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:635)
        at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:555)
        at java.lang.Thread.run(Thread.java:748)
09:53:49,775 INFO - Executing pre-execute action...
09:53:49,775 INFO - Running step...
09:53:50,059 INFO - Executing post-execute action...
09:53:50,059 ERROR - Step 'master>execute>execute-sequential-dispatch-groups>execute-parallel-dispatch-targets?dispatchTargetsVarName=dispatchTargets>execute-trigger-build?configName=build' is failed: Can not resolve requested build for configuration 'root/build'. Check server log for details.


Basically we tried to work around the problem described in QB-3224 by retrying the "Trigger other builds" step. But this did not work as the results of the tries after the first one seem to come out of a cache.