Maven: Non-resolvable parent POM

Just for reference.

The joys of Maven.

Putting the relative path of the modules to ../pom.xml solved it.

The parent element has a relativePath element that you need to point to the directory of the parent. It defaults to ..

It can also be fixed by putting the correct settings.xml file into the ~/.m2/ directory.

Alternative reason also might be the parent artifact comes from repository which is not accessible from pom.xml, typically private repository. The solution was to provide that repository in pom.xml:

<repositories>
    <repository>
        <id>internal-repo</id>
        <name>internal repository</name>
        <url>https://my/private/repo</url>
        <layout>default</layout>
        <releases>
            <enabled>true</enabled>
        </releases>
        <snapshots>
            <enabled>true</enabled>
        </snapshots>
    </repository>
</repositories>

In my case the problem was even more complicated due to Eclipse: the repository was active only in special profile (<profiles><profile><id>activate-private-repo</id><repositories>...) and Maven GUI in Eclipse didn't allow to set this profile through Ctrl+Alt+P shortcut.

The solution was to temporarily declare repository outside profile (unconditionally), launch Alt+F5 Maven Update Project, activate profile and put repository declaration back into profile. This is rather Eclipse bug, not Maven bug.

Just add <relativePath /> so the parent in pom should look like:

<parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.4.RELEASE</version>
        <relativePath />
    </parent>

Non-resolvable parent POM: This means you cannot resolve the parent repo.

Trun on debug mode:

[DEBUG] Reading global settings from **/usr/local/Cellar/maven/3.5.4/libexec/conf/settings.xml**
[DEBUG] **Reading user settings from /Users/username/.m2/settings.xml**
[DEBUG] Reading global toolchains from /usr/local/Cellar/maven/3.5.4/libexec/conf/toolchains.xml
[DEBUG] Reading user toolchains from /Users/username/.m2/toolchains.xml
[DEBUG] Using local repository at /Users/username/.m2/repository
[DEBUG] Using manager EnhancedLocalRepositoryManager with priority 10.0 for /Users/username/.m2/repository
[INFO] Scanning for projects...
[ERROR] [ERROR] Some problems were encountered while processing the POMs:

Because the parent repo is not part of the maven central. The solution is specify a setting.xml in ~m2/ to help result the parent POM. /Users/username/.m2/settings.xml

In that XML, you might need to specify the repository information.

verify if You have correct values in child POMs

GroupId
ArtefactId
Version

https://i.stack.imgur.com/sNwCu.png

If you build under a child project, then <relativePath> can help you resolve the parent pom.

install parent pom

But if you build the child project out of its folder, <relativePath> doesn't work. You can install the parent pom into your local repository first, then build the child project.

Replace <version>1.0_A0</version> with <version>${project.version}</version>

Run mvn once. This will download all the required repositories. You may switch back to 1.0_A0 after this step.

I had similar problem at my work.

Building the parent project without dependency created parent_project.pom file in the .m2 folder.

Then add the child module in the parent POM and run Maven build.

<modules>
    <module>module1</module>
    <module>module2</module>
    <module>module3</module>
    <module>module4</module>
</modules>

It was fixed when I removed settings.xml from .m2 folder.

I had the following config in the parent pom:

  <properties>
    <revision>1.0-SNAPSHOT</revision>
  </properties>

  <groupId>com.company.org</groupId>
  <artifactId>api-reactor-pom</artifactId>
  <version>$revision</version>
  <packaging>pom</packaging>

And I was getting 'Non-resolvable parent POM' error. I changed version to <version>1.0-SNAPSHOT</version>, and it's gone.

Apache Maven 3.6.3.

In this case the parent artifact is not found. As others pointed out, adding <relativePath/> to the pom where you reference a parent that cannot be found locally may work. But why does it work?

If the parent POM is not located in the parent folder, we need to use the relativePath tag to refer to the location. ... To skip the local file search and directly search the parent POM in Maven repositories, we need to explicitly set the relativePath to an empty value

as they explained here.

In other cases it will not work because the real reason is that Maven is unable to find the settings.xml which specifies the repositories to check for the parent artifact. E.g. when you try to build your Maven project from WSL2 (Linux shell on Windows) where you have not set up your Maven configuration.

In that case you need to create the settings.xml in the .m2 directory of WSL2 or create a reference to it, e.g. via a symbolic link. (That is a different issue but could be solved like this.)

In addition to the answer by Luke Willis, looks like this:

<parent>
    <groupId>com.example</groupId>
    <artifactId>some-module</artifactId>
    <version>1.0</version>
    <relativePath>../pom.xml</relativePath>
</parent>

Add a Dependency in

pom.xml:

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.1.8.RELEASE</version>
    <relativePath/> <!-- lookup parent from repository -->
</parent>
<dependency>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-resources-plugin</artifactId>
        <version>2.4.3</version>
</dependency>

I solved that problem on me after a very long try, I created another file named "parent_pom.xml" in child module file directory at local and pasted contents of parent_pom.xml,which is located at remote, to newly created "parent_pom.xml". It worked for me and error message has gone.

Inside relative path tag do as follows

<relative>{project_name}/pom.xml</relative>

and then RunAs-> Maven build

It worked for me.

I had the issue that two reactor build pom.xml files had the same artefactId.