gistfile1.txt

      <plugin>
        <groupId>org.eclipse.tycho</groupId>
        <artifactId>target-configuration</artifactId>
        <version>${tycho-version}</version>
        <configuration>

          <!--
            target runtime environments, affects project dependency resolution, 
            including contents of the target platform in some cases, and
            platform specific packaging, mostly RCP applications. 
          -->
          <environments>
            <environment>
              <os>linux</os>
              <ws>gtk</ws>
              <arch>x86_64</arch>
            </environment>
            <environment>
              <os>macosx</os>
              <ws>cocoa</ws>
              <arch>x86_64</arch>
            </environment>
          </environments>

          <!--
            Target execution environment (a.k.a. "java profile").
            affects dependency resolution, compilation, test execution.

            If execution environment configured in pom.xml is prefixed with question mark,
            it will be used as minimal execution environment, but higher level can be
            required by bundle manifest. This is useful to configure default value in
            parent pom.xml. Value without ``?'' prefix will be used as is, regardless of
            bundle manifest configuration.
          -->
          <executionEnvironment>?J2SE-1.5</executionEnvironment>

          <!--
          Target platform is the set of bundles, features and other artifacts and metadata
          used to resolve project dependencies. 
           -->
          <target-platform>
            <!-- remove, p2 is the only target platform resolver implementation -->
            <resolver>p2</resolver>

            <!--
             whether to use p2 repository mirrors or always download artifacts from the canonical repository url.
             default is to use mirrors.

             not sure if this should be under target-platform 
             -->
            <p2-mirrors>true|enable|false|disable</p2-mirrors>

            <!-- 
              whether to include or not artifacts defined as <dependency> pom.xml elements

              default is to ignore. 
            -->
            <pomDependencies>ignore|consider|include</pomDependencies>

            <!-- 
             -->
            <targets>
              <target>
                <artifact>
                  <groupId>org.eclipse.tycho</groupId>
                  <artifactId>tycho-bundles-target</artifactId>
                  <version>${project.version}</version>
                  <classifier>tycho</classifier>
                </artifact>
              </target>
            </targets>

            <filters />
          </target-platform>

          <dependency-resolver>
            <!--
            Whether optional dependencies should be treated as required (the default) or ignored. 
             -->
            <optionalDependencies>igore|require</optionalDependencies>

            <!-- 
              additional dependency resolution requirements
            -->
            <extraRequirements>
              <requirement>
                <type>eclipse-plugin</type>
                <id>org.eclipse.osgi</id>
                <versionRange>[3.4,3.5)</versionRange>
              </requirement>
            </extraRequirements>

            <!--
              This was originally introduced to support packaging of multiple versions of the same
              feature/bundle into a "deployable" feature. Not sure if we need this any more.
            -->
            <allowConflictingDependencies>true|false</allowConflictingDependencies>
          </dependency-resolver>
        </configuration>
      </plugin>