How to configure/override Maven property used as parent version in dependencies? - maven

Question

Suppose there are two 3rd-party Maven artifacts with the following POM.XMLs:
artifact1 POM.XML:
<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>group1</groupId>
<artifactId>artifact1</artifactId>
<version>${artifact1.version}</version>
<packaging>pom</packaging>
<properties>
<artifact1.version>0.0.1-SNAPSHOT</artifact1.version>
</properties>
<modules>
<module>../artifact2</module>
</modules>
artifact2 POM.XML:
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<artifactId>artifact2</artifactId>
<parent>
<groupId>group1</groupId>
<artifactId>artifact1</artifactId>
<version>${artifact1.version}</version>
<relativePath>../artifact1</relativePath>
</parent>
They are built normally using
mvn clean install
Now, if I try to reuse artifact2 in a 3rd POM.XML:
<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>group2</groupId>
<artifactId>artifact3</artifactId>
<version>0.0.1-SNAPSHOT</version>
<dependencies>
<dependency>
<groupId>group1</groupId>
<artifactId>artifact2</artifactId>
<version>0.0.1-SNAPSHOT</version>
</dependency>
</dependencies>
After executing...
mvn clean install
...the build fails trying to locate group1:artifact1:pom:${artifact1.version}
[ERROR] Failed to execute goal on project artifact3: Could not resolve dependencies for project group2:artifact3:jar:0.0.1-SNAPSHOT: Failed to collect dependencies at group1:artifact2:jar:0.0.1-SNAPSHOT: Failed to read artifact descriptor for group1:artifact2:jar:0.0.1-SNAPSHOT: Could not find artifact group1:artifact1:pom:${artifact1.version} in central (https://repo.maven.apache.org/maven2) -> [Help 1]
And setting the property in the command-line doesn't work either:
mvn clean install -Dartifact1.version=0.0.1-SNAPSHOT
How can I use artifact2 as a dependency?

Answer 1

<parent> doesn't allow variables. Because in order to get a list of variables Maven first has to build Effective POM and for this it needs to resolve parents.
Even if there is some version of Maven that allowed such module to be installed it's not a working solution in general. Maven's ideology is that all the dependencies (including parent) could be downloaded from a repo and are not necessarily present on local FS/in the reactor. With properties in the parent dependency definition you violate this rule.