You should probably wait and update to using version 3.7
of site plugin as mentioned here.
Seems like you are encountering something similar to #MSITE-796
Quoting further from the same link:-
The release will need a little bit more time due to pending
SNAPSHOT
-dependencies which need to be released first. So either have
a little bit more patience or add doxia-sitetools
1.7.5
as a dependency
to the maven-site-plugin in your own project.
<dependency>
<groupId>org.apache.maven.doxia</groupId>
<artifactId>doxia-sitetools</artifactId>
<version>1.7.5</version>
</dependency>
-edit-
As doxia-sitetools
is just a pom
container project one needs to update all of it's modules directly:
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-site-plugin</artifactId>
<version>3.6</version>
<dependencies>
<dependency>
<groupId>org.apache.maven.doxia</groupId>
<artifactId>doxia-decoration-model</artifactId>
<version>1.7.5</version>
</dependency>
<dependency>
<groupId>org.apache.maven.doxia</groupId>
<artifactId>doxia-skin-model</artifactId>
<version>1.7.5</version>
</dependency>
<dependency>
<groupId>org.apache.maven.doxia</groupId>
<artifactId>doxia-integration-tools</artifactId>
<version>1.7.5</version>
</dependency>
<dependency>
<groupId>org.apache.maven.doxia</groupId>
<artifactId>doxia-site-renderer</artifactId>
<version>1.7.5</version>
</dependency>
<dependency>
<groupId>org.apache.maven.doxia</groupId>
<artifactId>doxia-doc-renderer</artifactId>
<version>1.7.5</version>
</dependency>
</dependencies>
</plugin>