Generate yaml in maven multi project

[blegall]

I have a simple maven project containing only one dependency install on my maven cache (dependency containing classes annotated with swagger annotations. When I launch mvn install it does not generate documentation associated to those annotations.
Here my pom.xml :

<swagger2markup.plugin.version>1.3.3</swagger2markup.plugin.version>
<swagger2markup.extension.version>1.3.1</swagger2markup.extension.version>
<swagger-maven-plugin-version>3.1.5</swagger-maven-plugin-version>
</properties>
   <dependencies>
       <dependency>
               <groupId>com.my.compagny</groupId>
               <artifactId>gen-documentation</artifactId>
               <version>1.0-SNAPSHOT</version>
       </dependency>
   </dependencies>
  <build>
      <defaultGoal>process-resources</defaultGoal>
       <plugins>
              <plugin>
                       <groupId>com.github.kongchen</groupId>
                       <artifactId>swagger-maven-plugin</artifactId>
                       <version>${swagger-maven-plugin-version}</version>
                       <configuration>
                               <apiSources>
                                       <apiSource>
                                               <springmvc>true</springmvc>
                                               <locations>
                                                       <location>com.mypackage.to.annotated.classes.*</location>
                                                       </locations>
                                               <info>
                                                      <title>Swagger Sample App</title>
                                                      <description>This is a sample server Petstore server.</description>
                                                       <version>1.0</version>
                                              </info>
                                               <outputFormats>yaml</outputFormats>
                                               <swaggerDirectory>./src/docs</swaggerDirectory>
                                       </apiSource>
                               </apiSources>
                       </configuration>
                       <executions>
                               <execution>
                                       <phase>install</phase>
                                       <goals>
                                               <goal>generate</goal>
                                       </goals>
                               </execution>
                       </executions>
               </plugin>```
.....
Why does it not generate my yaml file ?