Maven tests run twice when a profile identifier is in multiple projects. Why? - maven

Question

I have numerous projects in IntelliJ, each of which has a pom.xml, and each of the projects' poms inherit from the master pom.xml. One profile (called test1) is present in two of the poms (for project2 and project4). When I run maven from the command line, specifying one project and the profile name, it works (the tests in that project are executed once) Here is the commmand:
mvn test -pl project2 -am -P test1
When I specify both projects (both of which have the same profile present), the tests in project4 are executed twice. Here is the command:
mvn test -pl project2,project4 -am -P test1
I would like the tests only to be executed once. I am running maven 3.1.1.
As a further complication, when I specify just project4, the tests in project2 get executed once, and the tests in project4 don't get executed at all. Here is the command:
mvn test -pl project4 -am -P test1
Here is pom.xml for project2:
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns stuff...>
<parent>
<artifactId>parent artifact id</artifactId>
<groupId>group id</groupId>
<version>version</version>
</parent>
<modelVersion>4.0.0</modelVersion>
<name>project2</name>
<artifactId>project2</artifactId>
<packaging>jar</packaging>
<profiles>
<profile>
<id>test1</id>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.9</version>
<executions>
<execution>
<id>execute-tests-1</id>
<phase>test</phase>
<goals>
<goal>test</goal>
</goals>
<configuration>
<skip>false</skip>
<excludes>
<exclude>com/path/to/exclude/**/*.java</exclude>
</excludes>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
</profile>
</profiles>
<build>
<plugins>
<!-- We don't want to run any tests without an active profile -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.9</version>
<configuration>
<skip>true</skip>
</configuration>
</plugin>
<!-- This exports the classes in the tests for use with our other modules' tests -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<version>2.2</version>
<executions>
<execution>
<goals>
<goal>test-jar</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
<dependencies>
[ dependencies ...]
</dependencies>
</project>
Here is the pom.xml for project4:
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns stuff>
<parent>
<artifactId>[parent artifact id]</artifactId>
<groupId>[group id]</groupId>
<version>[version]</version>
</parent>
<modelVersion>4.0.0</modelVersion>
<name>project4</name>
<artifactId>project4</artifactId>
<packaging>jar</packaging>
<dependencies>
[ dependencies ...]
</dependencies>
<profiles>
<profile>
<id>test1</id>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.9</version>
<executions>
<execution>
<id>execute-tests-2</id>
<phase>test</phase>
<goals>
<goal>test</goal>
</goals>
<configuration>
<includes>
<include>com/path/to/tests/*.java</include>
</includes>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
<dependencies>
[ dependencies...]
</dependencies>
</profile>
</profiles>
</project>

Answer 1

I figured out the answer to my own question (by looking carefully at some of our other projects' Maven test setup). I had to do two things:
Include a <skip>false</skip> element in the <configuration> aggregate in the surefire plugin.
Include a generic surefire <plugins> aggregate outside of the <profiles> section. This one has <skip> set to true and prevents tests being run unless they are in a profile. Here is what the section looks like:
<build>
<plugins>
<!-- We don't want to run any tests without an active profile -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.9</version>
<configuration>
<skip>true</skip>
</configuration>
</plugin>
</plugins>
</build>
The problem was that the tests were running the default-test lifecycle phase and then they were running again in the test phase. After I made the change they only ran in the test phase.