'dependencies.dependency.version' is missing error, but version is managed in parent

Question

I have a maven project that contains several modules. In Eclipse (Juno, with m2e) it seems to compile fine. But when I do a maven install on one of the modules, the build fails immediately.

Parent pom:

  <groupId>com.sw.system4</groupId>   <artifactId>system4-parent</artifactId>   <version>${system4.version}</version>   <packaging>pom</packaging>   <name>System 4 Parent Project</name>   <modules>     <module>system4-data</module>      ...others...   </modules>   <properties>     <system4.version>0.0.1-SNAPSHOT</system4.version>     <spring.version>3.2.3.RELEASE</spring.version>     ... others...   </properties>    <dependencyManagement>     <dependencies>       <dependency>         <groupId>org.springframework</groupId>         <artifactId>spring-core</artifactId>         <version>${spring.version}</version>         <scope>runtime</scope>       </dependency>     ... lots of others ...     </dependencies>   </dependencyManagement> 

Child pom:

  <parent>     <groupId>com.sw.system4</groupId>     <artifactId>system4-parent</artifactId>     <version>0.0.1-SNAPSHOT</version>   </parent>   <artifactId>system4-data</artifactId>   <dependencies>     <dependency>         <groupId>org.springframework</groupId>         <artifactId>spring-core</artifactId>         <scope>runtime</scope>     </dependency>     ... lots of others...   </dependencies> 

When I build, I get the following output:

[ERROR] The build could not read 1 project -> [Help 1] [ERROR] [ERROR]   The project com.sw.system4:system4-data:0.0.1-SNAPSHOT (C:\work\eclips e_workspaces\systemiv\system4-parent\system4-data\pom.xml) has 8 errors  [ERROR]     'dependencies.dependency.version' for org.springframework:spring-cor e:jar is missing. @ line 16, column 16  ... others omitted for clarity ... 

I dont understand why it doesn't even attempt to compile. Ive tried removing the runtime scope from parent and child, and it makes no difference. Please help!

Answer 1

A couple things I think you could try:

1. Put the literal value of the version in the child pom

   <dependency>   <groupId>org.springframework</groupId>   <artifactId>spring-core</artifactId>   <version>3.2.3.RELEASE</version>   <scope>runtime</scope> </dependency> 

2. Clear your .m2 cache normally located C:\Users\user.m2\repository. I would say I do this pretty frequently when I'm working in maven. Especially before committing so that I can be more confident CI will run. You don't have to nuke the folder every time, sometimes just your project packages and the .cache folder are enough.

3. Add a relativePath tag to your parent pom declaration

   <parent>   <groupId>com.mycompany.app</groupId>   <artifactId>my-app</artifactId>   <version>1</version>  <relativePath>../parent/pom.xml</relativePath> </parent> 

It looks like you have 8 total errors in your poms. I would try to get some basic compilation running before adding the parent pom and properties.

Answer 2

If anyone finds their way here with the same problem I was having, my problem was that I was missing the <dependencyManagement> tags around dependencies I had copied from the child pom.