[MDEP-833] dependency:properties parallel build NPE

**[Carsten Rohde](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=JIRAUSER284599)** opened **[MDEP-833](https://issues.apache.org/jira/browse/MDEP-833?redirect=false)** and commented

In a huge multimodule project, I get an NPE when building in parallel (see stacktrace below). I've encountered a similar problem with the Antrun-Plugin before (see stacktrace below) which I was able to work around by attaching the execution to a later phase.

The NPEs happen when accessing artifact#getFile which seems not to be present in early phases of parallel builds, so maybe this problem is down to how maven handles parallelism. In my case dependency:properties is attached to its default phase `initialize`

dependency:properties

 

```java
project.getProperties().setProperty( artifact.getDependencyConflictId(),                                          artifact.getFile().getAbsolutePath() );
```

[Permalink dependency-plugin](https://github.com/apache/maven-dependency-plugin/blob/673ef9f4d6d0119ea6dcf1b61134d1277720d3b5/src/main/java/org/apache/maven/plugins/dependency/PropertiesMojo.java#L81-L82)

 

[Permalink antrun-plugin](https://github.com/apache/maven-antrun-plugin/blob/5ec09d7b6b1b64c26d05367837d60f98ed4e0db4/src/main/java/org/apache/maven/plugins/antrun/AntRunMojo.java#L474)

 

Is there any workaround, I could try?

 

 

**Stacktrace dependency:properties**

 

```java
Execution default of goal org.apache.maven.plugins:maven-dependency-plugin:3.3.0:properties failed.
    at org.apache.maven.lifecycle.internal.MojoExecutor.doExecute2 (MojoExecutor.java:375)
    at org.apache.maven.lifecycle.internal.MojoExecutor.doExecute (MojoExecutor.java:351)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:215)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:171)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:163)
    at org.apache.maven.lifecycle.internal.MojoExecutor.executeForkedExecutions (MojoExecutor.java:508)
    at org.apache.maven.lifecycle.internal.MojoExecutor.doExecute (MojoExecutor.java:345)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:215)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:171)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:163)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:117)
    at org.apache.maven.lifecycle.internal.builder.multithreaded.MultiThreadedBuilder$1.call (MultiThreadedBuilder.java:210)
    at org.apache.maven.lifecycle.internal.builder.multithreaded.MultiThreadedBuilder$1.call (MultiThreadedBuilder.java:195)
    at java.util.concurrent.FutureTask.run (FutureTask.java:266)
    at java.util.concurrent.Executors$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)
Caused by: org.apache.maven.plugin.PluginExecutionException: Execution default of goal org.apache.maven.plugins:maven-dependency-plugin:3.3.0:properties failed.
    at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo (DefaultBuildPluginManager.java:148)
    at org.apache.maven.lifecycle.internal.MojoExecutor.doExecute2 (MojoExecutor.java:370)
    at org.apache.maven.lifecycle.internal.MojoExecutor.doExecute (MojoExecutor.java:351)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:215)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:171)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:163)
    at org.apache.maven.lifecycle.internal.MojoExecutor.executeForkedExecutions (MojoExecutor.java:508)
    at org.apache.maven.lifecycle.internal.MojoExecutor.doExecute (MojoExecutor.java:345)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:215)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:171)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:163)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:117)
    at org.apache.maven.lifecycle.internal.builder.multithreaded.MultiThreadedBuilder$1.call (MultiThreadedBuilder.java:210)
    at org.apache.maven.lifecycle.internal.builder.multithreaded.MultiThreadedBuilder$1.call (MultiThreadedBuilder.java:195)
    at java.util.concurrent.FutureTask.run (FutureTask.java:266)
    at java.util.concurrent.Executors$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)
Caused by: java.lang.NullPointerException
    at org.apache.maven.plugins.dependency.PropertiesMojo.execute (PropertiesMojo.java:82)
    at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo (DefaultBuildPluginManager.java:137)
    at org.apache.maven.lifecycle.internal.MojoExecutor.doExecute2 (MojoExecutor.java:370)
    at org.apache.maven.lifecycle.internal.MojoExecutor.doExecute (MojoExecutor.java:351)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:215)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:171)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:163)
    at org.apache.maven.lifecycle.internal.MojoExecutor.executeForkedExecutions (MojoExecutor.java:508)
    at org.apache.maven.lifecycle.internal.MojoExecutor.doExecute (MojoExecutor.java:345)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:215)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:171)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:163)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:117)
    at org.apache.maven.lifecycle.internal.builder.multithreaded.MultiThreadedBuilder$1.call (MultiThreadedBuilder.java:210)
    at org.apache.maven.lifecycle.internal.builder.multithreaded.MultiThreadedBuilder$1.call (MultiThreadedBuilder.java:195)
    at java.util.concurrent.FutureTask.run (FutureTask.java:266)
    at java.util.concurrent.Executors$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)
```

 

 

**Stacktrace antrun:run**

 

```java
 Error executing Ant tasks: null
    at org.apache.maven.lifecycle.internal.MojoExecutor.doExecute2 (MojoExecutor.java:375)
    at org.apache.maven.lifecycle.internal.MojoExecutor.doExecute (MojoExecutor.java:351)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:215)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:171)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:163)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:117)
    at org.apache.maven.lifecycle.internal.builder.multithreaded.MultiThreadedBuilder$1.call (MultiThreadedBuilder.java:210)
    at org.apache.maven.lifecycle.internal.builder.multithreaded.MultiThreadedBuilder$1.call (MultiThreadedBuilder.java:195)
    at java.util.concurrent.FutureTask.run (FutureTask.java:266)
    at java.util.concurrent.Executors$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)
Caused by: org.apache.maven.plugin.MojoExecutionException: Error executing Ant tasks: null
    at org.apache.maven.plugins.antrun.AntRunMojo.execute (AntRunMojo.java:323)
    at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo (DefaultBuildPluginManager.java:137)
    at org.apache.maven.lifecycle.internal.MojoExecutor.doExecute2 (MojoExecutor.java:370)
    at org.apache.maven.lifecycle.internal.MojoExecutor.doExecute (MojoExecutor.java:351)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:215)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:171)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:163)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:117)
    at org.apache.maven.lifecycle.internal.builder.multithreaded.MultiThreadedBuilder$1.call (MultiThreadedBuilder.java:210)
    at org.apache.maven.lifecycle.internal.builder.multithreaded.MultiThreadedBuilder$1.call (MultiThreadedBuilder.java:195)
    at java.util.concurrent.FutureTask.run (FutureTask.java:266)
    at java.util.concurrent.Executors$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)
Caused by: java.lang.NullPointerException
    at org.apache.maven.plugins.antrun.AntRunMojo.copyProperties (AntRunMojo.java:474)
    at org.apache.maven.plugins.antrun.AntRunMojo.execute (AntRunMojo.java:294)
    at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo (DefaultBuildPluginManager.java:137)
    at org.apache.maven.lifecycle.internal.MojoExecutor.doExecute2 (MojoExecutor.java:370)
    at org.apache.maven.lifecycle.internal.MojoExecutor.doExecute (MojoExecutor.java:351)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:215)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:171)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:163)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:117)
    at org.apache.maven.lifecycle.internal.builder.multithreaded.MultiThreadedBuilder$1.call (MultiThreadedBuilder.java:210)
    at org.apache.maven.lifecycle.internal.builder.multithreaded.MultiThreadedBuilder$1.call (MultiThreadedBuilder.java:195)
    at java.util.concurrent.FutureTask.run (FutureTask.java:266)
    at java.util.concurrent.Executors$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)
```

 

 

 

 

---

**Affects:** 3.3.0

Start in src/main/java/org/apache/maven/plugins/dependency/PropertiesMojo.java at line 81-82, where dependency:properties accesses artifact#getFile, and reproduce the failure with a parallel multimodule build using the initialize phase. Compare the reported Antrun reference if useful. Done means the affected parallel build no longer fails with a NullPointerException.

Written by the indexing model from the issue text.