Note since upgrading to v1.526 (early August) we hadn't seen this error again until today. But in this case, it does not seem as if there are multiple upstream jobs mentioned as a trigger.

Slightly different stack:

FATAL: null
java.lang.NullPointerException
at hudson.plugins.copyartifact.TriggeredBuildSelector.getBuild(TriggeredBuildSelector.java:61)
at hudson.plugins.copyartifact.TriggeredBuildSelector.getBuild(TriggeredBuildSelector.java:73)
at hudson.plugins.copyartifact.CopyArtifact.perform(CopyArtifact.java:199)
at hudson.tasks.BuildStepMonitor$1.perform(BuildStepMonitor.java:19)
at hudson.model.AbstractBuild$AbstractBuildExecution.perform(AbstractBuild.java:804)
at hudson.model.Build$BuildExecution.build(Build.java:199)
at hudson.model.Build$BuildExecution.doRun(Build.java:160)
at hudson.model.AbstractBuild$AbstractBuildExecution.run(AbstractBuild.java:586)
at hudson.model.Run.execute(Run.java:1597)
at hudson.model.FreeStyleBuild.run(FreeStyleBuild.java:46)
at hudson.model.ResourceController.execute(ResourceController.java:88)
at hudson.model.Executor.run(Executor.java:247)

Yesterday, I have seen this error in 3 of our jobs.
Two of them are configured to be triggered by one upstream job. One is configured to be triggered by two upstream jobs.
I do not believe that this issue has something to do with the number of upstream jobs.

Using locally configured password for connection to :pserver:secretuser@secrethost:/secretdir
cvs rlog -S -d06 Nov 2013 18:52:38 +0100<07 Nov 2013 19:26:46 +0100 secretcvsmodule
FATAL: null
java.lang.NullPointerException
at hudson.plugins.copyartifact.TriggeredBuildSelector.getBuild(TriggeredBuildSelector.java:61)
at hudson.plugins.copyartifact.TriggeredBuildSelector.getBuild(TriggeredBuildSelector.java:73)
at hudson.plugins.copyartifact.CopyArtifact.perform(CopyArtifact.java:254)
at hudson.tasks.BuildStepMonitor$1.perform(BuildStepMonitor.java:19)
at hudson.model.AbstractBuild$AbstractBuildExecution.perform(AbstractBuild.java:780)
at hudson.model.Build$BuildExecution.build(Build.java:199)
at hudson.model.Build$BuildExecution.doRun(Build.java:160)
at hudson.model.AbstractBuild$AbstractBuildExecution.run(AbstractBuild.java:565)
at hudson.model.Run.execute(Run.java:1592)
at hudson.model.FreeStyleBuild.run(FreeStyleBuild.java:46)
at hudson.model.ResourceController.execute(ResourceController.java:88)
at hudson.model.Executor.run(Executor.java:237)

We are using Jenkins 1.509.4 and Copy Artifact Plugin 1.28 on Linux.

It can be reproduced with following steps:

1. Create a free style project UPSTREAM
   • makes an artifact
   • triggers INTERMEDIATE
2. Create a free style project INTERMEDIATE
   • triggers DOWNSTREAM
3. Create a free style project DOWNSTREAM
   • set the quiet period to a long value.
   • copies an artifact from UPSTREAM with TriggeredBuildSelector
4. Launch UPSTREAM
5. After INTERMEDIATE finished and before DOWNSTREAM starts, delete the build of INTERMEDIATE.

https://github.com/jenkinsci/copyartifact-plugin/pull/46

Code changed in jenkins
User: ikedam
Path:
src/test/java/hudson/plugins/copyartifact/TriggeredBuildSelectorTest.java
src/test/java/hudson/plugins/copyartifact/testutils/RemoveUpstreamBuilder.java
http://jenkins-ci.org/commit/copyartifact-plugin/72435901fdaea4c9202a771b752f205e6eb69462
Log:
JENKINS-18804 Added a test to reproduce JENKINS-18804.

Code changed in jenkins
User: ikedam
Path:
src/main/java/hudson/plugins/copyartifact/TriggeredBuildSelector.java
http://jenkins-ci.org/commit/copyartifact-plugin/0af073471b7b630e6e3b9ca8e8984fd2bf2f9afa
Log:
[FIXED JENKINS-18804] Fixed NPE on TriggeredBuildSelector when the upstream is removed.

Code changed in jenkins
User: ikedam
Path:
src/main/java/hudson/plugins/copyartifact/TriggeredBuildSelector.java
src/test/java/hudson/plugins/copyartifact/TriggeredBuildSelectorTest.java
src/test/java/hudson/plugins/copyartifact/testutils/RemoveUpstreamBuilder.java
http://jenkins-ci.org/commit/copyartifact-plugin/22eb37c9763a1a67ebd199dbe507edabfc190068
Log:
Merge pull request #46 from ikedam/feature/JENKINS-18804_FixNPEonTriggeredBuildSelector

JENKINS-18804 Fix NPE in TriggeredBuildSelector

Compare: https://github.com/jenkinsci/copyartifact-plugin/compare/9f7f31b6bfec...22eb37c9763a