Dependency Resolution Troubleshooting

Problem

Your build fails with messages indicating that certain bundles, features, or packages cannot be found.

Solution

1. Check your target platform definition: Ensure all required p2 repositories are included in your target platform configuration
2. Verify repository URLs: Make sure all repository URLs in your target platform are accessible
3. Check bundle/feature IDs: Verify that the IDs of dependencies match exactly (case-sensitive)
4. Version ranges: Ensure version ranges in your dependencies are correct and match available versions

Problem

Multiple versions of the same bundle are available, causing conflicts or resolution failures.

Solution

1. Use explicit versions: In your target platform, specify exact versions instead of version ranges when possible
2. Review bundle imports: Check MANIFEST.MF for conflicting Import-Package or Require-Bundle declarations
3. Enable dependency resolution debugging: Add -X to your Maven command to see detailed resolution logs

Problem

Tycho complains about missing or invalid p2 metadata.

Solution

1. Check repository metadata: Verify that p2 repositories contain valid content.xml and artifacts.xml files
2. Update site refresh: If using local repositories, ensure they are properly generated
3. Clear local cache: Remove ~/.m2/repository/p2 to force re-download of metadata

Problem

Build fails when trying to resolve platform-specific fragments or bundles.

Solution

1. Configure target environments: In your target-platform-configuration, specify all target environments:

   <plugin>
     <groupId>org.eclipse.tycho</groupId>
     <artifactId>target-platform-configuration</artifactId>
     <version>${tycho-version}</version>
     <configuration>
       <environments>
         <environment>
           <os>linux</os>
           <ws>gtk</ws>
           <arch>x86_64</arch>
         </environment>
         <environment>
           <os>win32</os>
           <ws>win32</ws>
           <arch>x86_64</arch>
         </environment>
         <environment>
           <os>macosx</os>
           <ws>cocoa</ws>
           <arch>x86_64</arch>
         </environment>
       </environments>
     </configuration>
   </plugin>
   

2. Use platform filters: Check if your dependencies have platform-specific requirements

Problem

Your OSGi bundle depends on plain Maven artifacts that aren't available in p2 repositories.

Solution

1. Use pomDependencies: Configure target-platform-configuration to consider pom dependencies:

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

2. Wrap Maven artifacts: Use tools like bnd or tycho-extras to wrap Maven artifacts as OSGi bundles

Problem

Tycho reports circular dependencies between bundles.

Solution

1. Review bundle dependencies: Check your MANIFEST.MF files for circular Require-Bundle declarations
2. Use Import-Package: Prefer Import-Package over Require-Bundle to reduce coupling
3. Split packages: Avoid split packages (same package in multiple bundles)
4. Refactor: Consider refactoring to break circular dependencies

Problem

Target platform is not being picked up correctly.

Solution

1. Verify target file location: Ensure the path to your .target file is correct
2. Check target file syntax: Validate your .target file is well-formed XML
3. Activation: Make sure the target definition is activated (has <activation>true</activation>)

Enable Verbose Logging

Run Maven with -X or -Ddebug to get detailed dependency resolution information:

mvn clean install -X

List Resolved Dependencies

Use the list-dependencies goal to see what Tycho has resolved:

mvn org.eclipse.tycho:tycho-maven-plugin:list-dependencies

Dependency Tree

View the dependency tree for your project:

mvn dependency:tree