mvn clean without dependencies

Question

I have a third party jar which is necessary for our project. It is not available on the central maven repository, so I used the maven-install-plugin to install the jar locally during a build. I tied the "install-file" goal to the "validate" phase, and this mostly works. The pom.xml file excerpt is below:

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
...
<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-install-plugin</artifactId>
            <version>2.3</version>
            <executions>
                <execution>
                    <id>install-myartifact</id>
                    <phase>validate</phase>
                    <goals>
                        <goal>install-file</goal>
                    </goals>
                    <configuration>
                        <file>${basedir}/lib/myartifact-1.2.3.jar</file>
                        <groupId>com.example</groupId>
                        <artifactId>myartifact</artifactId>
                        <version>1.2.3</version>
                        <packaging>jar</packaging>
                        <generatePom>true</generatePom>
                    </configuration>
                </execution>
            </executions>
        </plugin>
    </plugins>
</build>
<dependencies>
    <dependency>
        <groupId>com.example</groupId>
        <artifactId>myartifact</artifactId>
        <version>1.2.3</version>
    </dependency>
</dependencies>

However, there's a catch. Most of our developers and our Jenkins installation run "mvn clean install." The "validate" phase is not part of the "clean" lifecycle, and clean inexplicably requires all the dependencies be present to run. So the first time someone runs this build, it does not work.

[INFO] Scanning for projects...
[INFO] ------------------------------------------------------------------------
[INFO] Building MyModule
[INFO]    task-segment: [clean, install]
[INFO] ------------------------------------------------------------------------
[INFO] [clean:clean]
[INFO] Deleting directory C:\svn\trunk\mymodule\target
Downloading: http://nexusserver.local:8080/nexus/content/groups/public/com/example/myartifact-1.2.3.pom
[INFO] Unable to find resource 'com.example:myartifact:pom:1.2.3' in repository central (http://central)
[INFO] ------------------------------------------------------------------------
[ERROR] BUILD ERROR
[INFO] ------------------------------------------------------------------------
[INFO] Failed to resolve artifact.

Missing:
----------
1) com.example:myartifact:jar:1.2.3

  Try downloading the file manually from the project website.

  Then, install it using the command: 
      mvn install:install-file -DgroupId=com.example -DartifactId=myartifact -Dversion=1.2.3 -Dpackaging=jar -Dfile=/path/to/file

  Alternatively, if you host your own repository you can deploy the file there: 
      mvn deploy:deploy-file -DgroupId=com.example -DartifactId=myartifact -Dversion=1.2.3 -Dpackaging=jar -Dfile=/path/to/file -Durl=[url] -DrepositoryId=[id]

  Path to dependency: 
    1) com.example:mymodule:war:0.0.1-SNAPSHOT
    2) com.example:myartifact:jar:1.2.3

----------
1 required artifact is missing.

for artifact: 
  com.example:mymodule:war:0.0.1-SNAPSHOT

from the specified remote repositories:
  nexus (http://nexusserver.local:8080/nexus/content/groups/public)



[INFO] ------------------------------------------------------------------------
[INFO] For more information, run Maven with the -e switch
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 1 second
[INFO] Finished at: Thu Jun 09 11:01:24 EDT 2011
[INFO] Final Memory: 17M/247M
[INFO] ------------------------------------------------------------------------

If I were to run simply "mvn install", the jar is installed during "validate," and I can run "mvn clean install" in subsequent builds. However, our build server does not have that flexibility. I've considered the following:

1. Moving the phase to "pre-clean," but that assumes everyone always uses clean the first time. It wouldn't help if someone ran simply "mvn install."
2. Copying the execution, with one occurring during "pre-clean" and one occurring during "validate." This covers all the bases, but the copied code leaves a bad taste.

Ideally, I'd love some other option. Is it possible to run clean without dependencies? Or to run a plugin twice without having to fully copy the execution? Thanks!

Answer 1

I ran into a related issue, and I found this question when googling for a solution, so I'll note it here:

mvn clean fails in a multi-module project when there are missing dependencies within the same project, if plugins are invoked during clean.

We invoke the antrun-plugin during the clean phase in some modules, and because of that all dependencies need to be present in the maven repository, including the other modules in the same reactor, which in some cases have not been built yet (say you just bumped the project version, or you're starting off a new project).

This is a maven-antrun bug reported in https://issues.apache.org/jira/browse/MANTRUN-78 - which again leads back to a bug in maven core: https://issues.apache.org/jira/browse/MNG-3283.

My workaround was to provide the developers (and Jenkins) with an alternative way of doing clean (shell/bat script, ant script or some git/hg clean operation), and have them invoke this instead.

I would suggest a similar workaround for your team (or just set up up a shared maven repository internally in your team, use one of the developer machines if necessary).

Answer 2

It looks like you're using nexus. It might be easier to deploy the artifact to the nexus repo as opposed to having to maintain it with this project.