'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.