| name | tycho-build-and-target-platform |
| description | Guidance for Tycho, target-platform, p2, feature, category, and Eclipse dependency/build alignment. |
Tycho Build and Target Platform
Use this skill when working on tasks related to:
.target files- Tycho or Maven build configuration
- target-platform alignment
- p2 repositories
- installable units
feature.xmlcategory.xml- dependency resolution in Eclipse plugin builds
- execution environment alignment
- bundle availability on the supported Eclipse baseline
Goal
Keep the build reproducible and compatible with the repository's minimum supported:
- Eclipse target-platform
- JDK
- bundle dependency set
Working Approach
1. Treat target-platform as the source of truth
When deciding whether a dependency, plugin, feature, or API can be used, first check whether it is available and compatible in the configured target-platform.
Do not assume a dependency is valid simply because it exists in Maven Central or works in a plain Java project.
2. Keep Tycho and metadata aligned
When build-related changes are made, check the consistency among:
.target files- parent and module
pom.xml
- Tycho plugins and configuration
META-INF/MANIFEST.MFfeature.xmlcategory.xml- p2 repository definitions
- execution environment or compiler target settings
A correct solution usually requires these files to remain aligned, not just one of them.
3. Minimize dependency expansion
When adding dependencies:
- add only what is necessary
- prefer dependencies already available in the current target-platform
- avoid broadening bundle requirements unnecessarily
- avoid introducing optional complexity unless there is a clear need
Be careful with transitive assumptions. Tycho and OSGi resolution are stricter than plain Maven dependency resolution.
4. Respect execution environment and JDK boundaries
Do not change Java execution environment, compiler target level, or required JDK assumptions unless explicitly requested.
If the task requires a newer Java level or newer platform baseline, call that out clearly instead of silently upgrading constraints.
5. Feature and p2 consistency
If the repository publishes features, update sites, or p2 metadata:
- ensure newly required bundles are reflected where needed
- ensure features include the right plugins and fragments
- ensure category definitions remain valid
- keep installable content and runtime requirements synchronized
Do not update only the plugin dependency while forgetting the publishable artifacts.
6. Prefer stable build changes
For Tycho-related updates:
- prefer minimal version changes
- avoid unnecessary plugin upgrades
- avoid broad build modernization unless explicitly requested
- keep build configuration understandable and repository-consistent
7. Diagnose resolution issues carefully
When build failures are related to Tycho or target-platform, consider:
- missing bundles in the target-platform
- mismatched bundle versions
- execution environment mismatch
- missing feature inclusion
- wrong p2 repository or category content
Require-Bundle vs Import-Package implications- platform-specific fragments or native dependencies
- test bundles requiring additional runtime content
Build Alignment Checklist
Before considering a build-related task complete, check:
- dependency exists in the configured target-platform
- dependency is compatible with the minimum supported Eclipse version
- dependency is compatible with the minimum supported JDK
MANIFEST.MF is aligned with actual usage.target files are still validpom.xml and Tycho config remain consistentfeature.xml is updated if installable content changedcategory.xml is updated if published content changed- p2 repository definitions remain correct
- no unnecessary platform baseline upgrade was introduced
Output Expectations
When proposing or implementing Tycho or target-platform changes, include relevant notes about:
- why the dependency or bundle is expected to resolve in the configured target-platform
- whether
MANIFEST.MF, .target, pom.xml, feature.xml, or category.xml also need updates
- whether the task changes the supported platform or JDK baseline
- any risk to reproducible builds, p2 publishing, or installable content
