[FIXED] Jenkins fails to build multi-module Maven project

Issue

I have a multi-module Maven project where I have multiple micro services as modules so I have modules listed in my parent pom.xml like below:

<modules>
    <module>core</module>
    <module>model-base</module>
    <module>module1</module>
    <module>module2</module>
    ...
    <module>module5</module>
    <module>module7</module>
    <module>module6</module>
</modules>

Here the module7 is dependent on module5, 6 so I have dependencies listed like below in my module7 pom.xml:

<parent>
    <artifactId>pojectA</artifactId>
    <groupId>com.domain</groupId>
    <version>1.0-SNAPSHOT</version>
</parent>
<modelVersion>4.0.0</modelVersion>
<artifactId>module7</artifactId>
<dependencies>
    <dependency>
        <groupId>com.domain</groupId>
        <artifactId>core</artifactId>
        <version>1.0-SNAPSHOT</version>
    </dependency>
    <dependency>
        <groupId>com.domain</groupId>
        <artifactId>module5</artifactId>
        <version>1.0-SNAPSHOT</version>
    </dependency>
    <dependency>
        <groupId>com.domain</groupId>
        <artifactId>module6</artifactId>
        <version>1.0-SNAPSHOT</version>
    </dependency>
</dependencies> 

When I run mvn clean package in my local the module5, 6 called before the module7 as expected but in Jenkins it is trying to build module 5 then module7 making build fail saying:

[ERROR] Failed to execute goal on project module7: Could not resolve dependencies for project module7:jar:1.0-SNAPSHOT: Could not find artifact module6:jar:1.0-SNAPSHOT -> [Help 1]

Do I need to run any other jobs or re-order the modules in my pom.xml, how is it differ from local to Jenkins? Appreciate any help on this.

Solution

As is probably quite well understood, the issue is that the dependencies between the child modules fail because they aren't installed in the local repository yet (because they are yet to be built). The goal that causes this (for me anyway) is mvn test, which is invoked by mvn package. Your local build probably works because at some point you've done a mvn install and this has bootstrapped your system.

In Jenkins the only way I've found to make these builds work is to use the Pre-build step invoking a Maven target of install, and then build the main step as usual.

Answered By - Nigel