complex profile behaviour

[Delany]

In my project snapshot/release repositories are configured
in a parent pom
in 2 mutually exclusive profiles
activated by the presence or absence of a property.

Its the same repos in each profile, but with different update intervals.
Flatten mode "defaults" runs in phase "initialize".

I found that my repositories tag was not included in the flattened pom.
Then I saw https://www.mojohaus.org/flatten-maven-plugin/flatten-mojo.html
that profiles are not resolved, but should be included in the flattened pom. But there are no profiles in the flatten pom either.

So I made this test project

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>com.mycompany.app</groupId>
  <artifactId>my-app</artifactId>
  <version>${revision}${changelist}</version>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <maven.compiler.source>1.7</maven.compiler.source>
    <maven.compiler.target>1.7</maven.compiler.target>
  </properties>

  <profiles>
    <profile>
      <id>repo</id>
      <activation>
        <property>
          <name>changelist</name>
        </property>
      </activation>
      <repositories>
        <repository>
          <id>repo.jenkins-ci.org</id>
          <url>https://repo.jenkins-ci.org/public/</url>
        </repository>
      </repositories>
    </profile>
  </profiles>

  <build>
    <plugins>
      <plugin>
        <groupId>org.codehaus.mojo</groupId>
        <artifactId>flatten-maven-plugin</artifactId>
        <version>1.3.0</version>
        <configuration>
          <updatePomFile>true</updatePomFile>
          <flattenMode>defaults</flattenMode>
          <flattenDependencyMode>direct</flattenDependencyMode>
        </configuration>
        <executions>
          <execution>
            <id>flatten</id>
            <goals>
              <goal>flatten</goal>
            </goals>
            <phase>initialize</phase>
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>
</project>

mvn initialize -Drevision=2.4.2 -Dchangelist=-SNAPSHOT && cat .flattened-pom.xml

I see my profiles are added. I was expecting "only the Activation and the Dependency dependencies of a Profile are copied to the flattened POM" but here I see the repositories.

<?xml version="1.0" encoding="UTF-8"?>
<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.mycompany.app</groupId>
  <artifactId>my-app</artifactId>
  <version>2.4.2-SNAPSHOT</version>
  <profiles>
    <profile>
      <id>repo</id>
      <activation>
        <property>
          <name>changelist</name>
        </property>
      </activation>
      <repositories>
        <repository>
          <id>repo.jenkins-ci.org</id>
          <url>https://repo.jenkins-ci.org/public/</url>
        </repository>
      </repositories>
    </profile>
  </profiles>
</project>

I gave up on configuring repositories in profiles.