Hi Gilbert,
When you build your plugin with sonar-plugin-api 8.8.0.42792, we can only assume your plugin is compatible with 8.8 and later.
If you are sure to not use an API introduced recently, you can compile with latest (e.g. 8.8), but still advertise your plugin as compatible with older versions (like 7.9), using property <sonarQubeMinVersion>7.9</sonarQubeMinVersion> in your pom.
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