Maven flatten plugin not working does not substitute my version property - maven

Question

For some reason when i do mvn install and check my local repo and look at the pom there, i don't see that the version variable was substituted with the value.
I am using a parent pom with a version in the properties
<properties>
<maven.javadoc.skip>true</maven.javadoc.skip>
<revision>19.3.29</revision>
</properties>
It also contains the flatten plugin entry:
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>flatten-maven-plugin</artifactId>
<version>1.2.2</version>
<configuration>
<updatePomFile>true</updatePomFile>
<flattenMode>resolveCiFriendliesOnly</flattenMode>
</configuration>
<executions>
<execution>
<id>flatten</id>
<phase>process-resources</phase>
<goals>
<goal>flatten</goal>
</goals>
</execution>
<execution>
<id>flatten.clean</id>
<phase>clean</phase>
<goals>
<goal>clean</goal>
</goals>
</execution>
</executions>
</plugin>
The child pom uses the ${revision} as the value for the version & ${project.version} for dependencies as recommended by maven:
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<artifactId>analysisModule</artifactId>
<version>${revision}</version>
<parent>
<groupId>com.mycompany.analysis</groupId>
<version>1.0.0</version>
<artifactId>autoav</artifactId>
<relativePath>../autoAV</relativePath>
</parent>
<build>
<resources>
<resource>
<directory>src/main/resources</directory>
<filtering>true</filtering>
</resource>
</resources>
</build>
<dependencies>
<dependency>
<groupId>com.mycompany.analysis</groupId>
<artifactId>analysisCore</artifactId>
<version>${project.version}</version>
</dependency>
</dependencies>
</project>
Looking at the local repo pom xml after I 'mvn install' :
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<artifactId>analysisJdbc</artifactId>
<version>${revision}</version>
<description>analysis of jdbc sources</description>
<parent>
<groupId>com.mycompany.analysis</groupId>
<version>1.0.0</version>
<artifactId>autoav</artifactId>
<relativePath>../autoAV</relativePath>
</parent>
<build>
<resources>
<resource>
<directory>src/main/resources</directory>
<filtering>true</filtering>
</resource>
</resources>
</build>
<dependencies>
<dependency>
<groupId>com.mycompany.analysis</groupId>
<artifactId>analysisCore</artifactId>
<version>${project.version}</version>
</dependency>
...
</project>
Shouldn't the ${revision} & ${project.version} been replaced with the actual numbers ?
Isn't that the whole thing about using flatten plugin ?
I followed this
https://www.mojohaus.org/flatten-maven-plugin/examples/example-central-version.html
Adding my output of mvn install (skipping tests) (maven version 3.3.9):
02:12:03 :/code/thedrs/gitrepos/analysis/analysis/analysisJdbc (main) $ mvn install -Dmaven.test.skip=true
[INFO] Scanning for projects...
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building analysisJdbc 19.3.30
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) # analysisJdbc ---
[WARNING] File encoding has not been set, using platform encoding UTF-8, i.e. build is platform dependent!
[WARNING] Using platform encoding (UTF-8 actually) to copy filtered resources, i.e. build is platform dependent!
[INFO] Copying 1 resource
[INFO]
[INFO] --- maven-compiler-plugin:3.1:compile (default-compile) # analysisJdbc ---
[INFO] Nothing to compile - all classes are up to date
[INFO]
[INFO] --- maven-resources-plugin:2.6:testResources (default-testResources) # analysisJdbc ---
[INFO] Not copying test resources
[INFO]
[INFO] --- maven-compiler-plugin:3.1:testCompile (default-testCompile) # analysisJdbc ---
[INFO] Not compiling test sources
[INFO]
[INFO] --- maven-surefire-plugin:2.12.4:test (default-test) # analysisJdbc ---
[INFO] Tests are skipped.
[INFO]
[INFO] --- maven-jar-plugin:2.4:jar (default-jar) # analysisJdbc ---
[INFO] Building jar: /code/thedrs/gitrepos/analysis/analysis/analysisJdbc/target/analysisJdbc-19.3.30.jar
[INFO] META-INF/maven/com.mycompany.analysis/analysisJdbc/pom.xml already added, skipping
[INFO] META-INF/maven/com.mycompany.analysis/analysisJdbc/pom.properties already added, skipping
[INFO]
[INFO] --- maven-install-plugin:2.4:install (default-install) # analysisJdbc ---
[INFO] Installing /code/thedrs/gitrepos/analysis/analysis/analysisJdbc/target/analysisJdbc-19.3.30.jar to /code/thedrs/.m2/com/mycompany/analysis/analysisJdbc/19.3.30/analysisJdbc-19.3.30.jar
[INFO] Installing /code/thedrs/gitrepos/analysis/analysis/analysisJdbc/pom.xml to /code/thedrs/.m2/com/mycompany/analysis/analysisJdbc/19.3.30/analysisJdbc-19.3.30.pom
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 6.147 s
[INFO] Finished at: 2020-05-06T02:12:40-07:00
[INFO] Final Memory: 14M/356M
[INFO] ------------------------------------------------------------------------

Answer 1

You need to move the plugin from <pluginManagement><plugins> to <plugins>. Alternatively, you can leave it there and just add a short plugin definition (including groupId and artifactId) to the <plugins> section.
<pluginManagement> is just to preconfigure version numbers and configuration. Plugins in <pluginManagement> are not run during the build unless they reappear in <plugins>.

Answer 2

I've been able to achieve that by creating another property for the dependencies. This property will have the same value as ${revision} and will be replaced in the generated pom file.
<properties>
<revision>19.3.29</revision>
<my-lib.version>${revision}</my-lib.version>
</properties>
Then instead of using ${project.version} in your dependencies, use your property:
<dependency>
<groupId>com.mycompany.analysis</groupId>
<artifactId>analysisCore</artifactId>
<version>${my-lib.version}</version>
</dependency>