"Unknown packaging: eclipse-plugin" in Maven - maven

Question

I want to build a project in Maven using eclipse-plugin packaging, but I get the following error for my POM:
[ERROR] Unknown packaging: eclipse-plugin # line 15, column 13 .
pom.xml:
<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/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<relativePath>../releng/pom.xml</relativePath>
<groupId>net.sf.logsaw</groupId>
<artifactId>parent</artifactId>
<version>1.0.0-SNAPSHOT</version>
</parent>
<artifactId>net.sf.logsaw.core</artifactId>
<version>1.0.4-SNAPSHOT</version>
<packaging>eclipse-plugin</packaging>
<name>LogSaw Core Plugin</name>
</project>

Answer 1

The packaging type eclipse-plugin is defined by a Maven build extension called Tycho. In order to use Tycho's packaging types, you need to configure Tycho as a build extension:
<build>
<plugins>
<plugin>
<groupId>org.eclipse.tycho</groupId>
<artifactId>tycho-maven-plugin</artifactId>
<version>${tycho-version}</version>
<extensions>true</extensions>
</plugin>
</plugins>
</build>
Also, Tycho requires additional metadata files to be present, e.g. an OSGi manifest for eclipse-plugin modules. Another major difference of a Tycho project compared to a regular Maven project is that you have to configure the so-called target platform, e.g. by defining a repository with layout=p2, in case your project references any external artifacts. To get started, you may have a look at this example project.
For more information, you can also check out Tycho's documentation wiki, e.g. the reference card page.