Non resolvable parent POM although relativePath set to existing parent pom.xml

Question

My project has the structure

pom.xml  (parent)
tcp/pom.xml
spark/pom.xml

The module xmls' both include this blurb

<parent>
  <groupId>org.myorg</groupId>
  <artifactId>parent</artifactId>
  <version>1.0</version>
  <relativePath>../pom.xml</relativePath>
</parent>

I have also tried leaving relativePath blank, or to ../ or .. or even not including it at all . In all cases the result is:

[ERROR] The build could not read 2 projects -> [Help 1]
[ERROR]
[ERROR]   The project org.myorg:tcpclient:1.0.0 (/git/MYorg/tcp/pom.xml) has 1 error
[ERROR]     Non-resolvable parent POM for org.myorg:tcpclient:1.0.0: 
 Failure to find org.myorg:parent:pom:1.0 in https://repository.apache.org/content/repositories/snapshots was cached in 
   the local repository, resolution will not be reattempted until 
   the update interval of Maven snapshots repository has elapsed or updates 
are forced and 'parent.relativePath' points at wrong local POM @ line 24, 
 column 9 -> [Help 2]

So I could use some help getting off the ground with these multi modules builds.

Update Following is last part of output of

mvn clean install -U  -X > out 2>&1


INFO] Error stacktraces are turned on.
[DEBUG] Reading global settings from /usr/local/Cellar/maven/3.3.9/libexec/conf/settings.xml
[DEBUG] Reading user settings from /Users/steve/.m2/settings.xml
[DEBUG] Reading global toolchains from /usr/local/Cellar/maven/3.3.9/libexec/conf/toolchains.xml
[DEBUG] Reading user toolchains from /Users/steve/.m2/toolchains.xml
[DEBUG] Using local repository at /Users/steve/.m2/repository
[DEBUG] Using manager EnhancedLocalRepositoryManager with priority 10.0 for /Users/steve/.m2/repository
[INFO] Scanning for projects...
[DEBUG] Using transporter WagonTransporter with priority -1.0 for https://repository.apache.org/content/repositories/snapshots
[DEBUG] Using connector BasicRepositoryConnector with priority 0.0 for https://repository.apache.org/content/repositories/snapshots
Downloading: https://repository.apache.org/content/repositories/snapshots/org/openchai/parent/1.0/parent-1.0.pom

[DEBUG] Writing tracking file /Users/steve/.m2/repository/org/openchai/parent/1.0/parent-1.0.pom.lastUpdated
[DEBUG] Using transporter WagonTransporter with priority -1.0 for https://repo.maven.apache.org/maven2
[DEBUG] Using connector BasicRepositoryConnector with priority 0.0 for https://repo.maven.apache.org/maven2
Downloading: https://repo.maven.apache.org/maven2/org/openchai/parent/1.0/parent-1.0.pom

[DEBUG] Writing tracking file /Users/steve/.m2/repository/org/openchai/parent/1.0/parent-1.0.pom.lastUpdated
[DEBUG] Skipped remote request for org.openchai:parent:pom:1.0, already updated during this session.
[DEBUG] Extension realms for project org.openchai:parent:pom:1.0.0: (none)
[DEBUG] Looking up lifecyle mappings for packaging pom from ClassRealm[plexus.core, parent: null]
[ERROR] [ERROR] Some problems were encountered while processing the POMs:
[WARNING] 'build.plugins.plugin.(groupId:artifactId)' must be unique but found duplicate declaration of plugin org.apache.maven.plugins:maven-jar-plugin @ line 223, column 21
[FATAL] Non-resolvable parent POM for org.openchai:tcpclient:1.0.0: Could not find artifact org.openchai:parent:pom:1.0 in Maven snapshots repository (https://repository.apache.org/content/repositories/snapshots) and 'parent.relativePath' points at wrong local POM @ line 24, column 9
[FATAL] Non-resolvable parent POM for org.openchai:spark_p2prdd:1.0.0: Failure to find org.openchai:parent:pom:1.0 in https://repo.maven.apache.org/maven2 was cached in the local repository, resolution will not be reattempted until the update interval of central has elapsed or updates are forced and 'parent.relativePath' points at wrong local POM @ line 24, column 10
[WARNING] 'build.plugins.plugin.version' for org.apache.maven.plugins:maven-install-plugin is missing. @ line 90, column 21
[WARNING] 'build.plugins.plugin.version' for org.apache.maven.plugins:maven-source-plugin is missing. @ line 168, column 15
 @ 
[ERROR] The build could not read 2 projects -> [Help 1]
org.apache.maven.project.ProjectBuildingException: Some problems were encountered while processing the POMs:
[WARNING] 'build.plugins.plugin.(groupId:artifactId)' must be unique but found duplicate declaration of plugin org.apache.maven.plugins:maven-jar-plugin @ line 223, column 21
[FATAL] Non-resolvable parent POM for org.openchai:tcpclient:1.0.0: Could not find artifact org.openchai:parent:pom:1.0 in Maven snapshots repository (https://repository.apache.org/content/repositories/snapshots) and 'parent.relativePath' points at wrong local POM @ line 24, column 9
[FATAL] Non-resolvable parent POM for org.openchai:spark_p2prdd:1.0.0: Failure to find org.openchai:parent:pom:1.0 in https://repo.maven.apache.org/maven2 was cached in the local repository, resolution will not be reattempted until the update interval of central has elapsed or updates are forced and 'parent.relativePath' points at wrong local POM @ line 24, column 10
[WARNING] 'build.plugins.plugin.version' for org.apache.maven.plugins:maven-install-plugin is missing. @ line 90, column 21
[WARNING] 'build.plugins.plugin.version' for org.apache.maven.plugins:maven-source-plugin is missing. @ line 168, column 15

    at org.apache.maven.project.DefaultProjectBuilder.build(DefaultProjectBuilder.java:422)
    at org.apache.maven.graph.DefaultGraphBuilder.collectProjects(DefaultGraphBuilder.java:419)
    at org.apache.maven.graph.DefaultGraphBuilder.getProjectsForMavenReactor(DefaultGraphBuilder.java:410)
    at org.apache.maven.graph.DefaultGraphBuilder.build(DefaultGraphBuilder.java:83)
    at org.apache.maven.DefaultMaven.buildGraph(DefaultMaven.java:491)
    at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:219)
    at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:193)
    at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:106)
    at org.apache.maven.cli.MavenCli.execute(MavenCli.java:863)
    at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:288)
    at org.apache.maven.cli.MavenCli.main(MavenCli.java:199)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:289)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229)
    at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415)
    at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356)
[ERROR]   
[ERROR]   The project org.openchai:tcpclient:1.0.0 (/git/OCspark/tcp/pom.xml) has 1 error
[ERROR]     Non-resolvable parent POM for org.openchai:tcpclient:1.0.0: Could not find artifact org.openchai:parent:pom:1.0 in Maven snapshots repository (https://repository.apache.org/content/repositories/snapshots) and 'parent.relativePath' points at wrong local POM @ line 24, column 9 -> [Help 2]
org.apache.maven.model.resolution.UnresolvableModelException: Could not find artifact org.openchai:parent:pom:1.0 in Maven snapshots repository (https://repository.apache.org/content/repositories/snapshots)
    at org.apache.maven.project.ProjectModelResolver.resolveModel(ProjectModelResolver.java:197)
    at org.apache.maven.project.ProjectModelResolver.resolveModel(ProjectModelResolver.java:246)
    at org.apache.maven.model.building.DefaultModelBuilder.readParentExternally(DefaultModelBuilder.java:1000)
    at org.apache.maven.model.building.DefaultModelBuilder.readParent(DefaultModelBuilder.java:800)
    at org.apache.maven.model.building.DefaultModelBuilder.build(DefaultModelBuilder.java:329)
    at org.apache.maven.project.DefaultProjectBuilder.build(DefaultProjectBuilder.java:469)
    at org.apache.maven.project.DefaultProjectBuilder.build(DefaultProjectBuilder.java:438)
    at org.apache.maven.project.DefaultProjectBuilder.build(DefaultProjectBuilder.java:555)
    at org.apache.maven.project.DefaultProjectBuilder.build(DefaultProjectBuilder.java:438)
    at org.apache.maven.project.DefaultProjectBuilder.build(DefaultProjectBuilder.java:401)
    at org.apache.maven.graph.DefaultGraphBuilder.collectProjects(DefaultGraphBuilder.java:419)
    at org.apache.maven.graph.DefaultGraphBuilder.getProjectsForMavenReactor(DefaultGraphBuilder.java:410)
    at org.apache.maven.graph.DefaultGraphBuilder.build(DefaultGraphBuilder.java:83)
    at org.apache.maven.DefaultMaven.buildGraph(DefaultMaven.java:491)
    at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:219)
    at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:193)
    at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:106)
    at org.apache.maven.cli.MavenCli.execute(MavenCli.java:863)
    at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:288)
    at org.apache.maven.cli.MavenCli.main(MavenCli.java:199)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:289)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229)
    at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415)
    at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356)
Caused by: org.eclipse.aether.resolution.ArtifactResolutionException: Could not find artifact org.openchai:parent:pom:1.0 in Maven snapshots repository (https://repository.apache.org/content/repositories/snapshots)
    at org.eclipse.aether.internal.impl.DefaultArtifactResolver.resolve(DefaultArtifactResolver.java:444)
    at org.eclipse.aether.internal.impl.DefaultArtifactResolver.resolveArtifacts(DefaultArtifactResolver.java:246)
    at org.eclipse.aether.internal.impl.DefaultArtifactResolver.resolveArtifact(DefaultArtifactResolver.java:223)
    at org.eclipse.aether.internal.impl.DefaultRepositorySystem.resolveArtifact(DefaultRepositorySystem.java:294)
    at org.apache.maven.project.ProjectModelResolver.resolveModel(ProjectModelResolver.java:193)
    ... 27 more
Caused by: org.eclipse.aether.transfer.ArtifactNotFoundException: Could not find artifact org.openchai:parent:pom:1.0 in Maven snapshots repository (https://repository.apache.org/content/repositories/snapshots)
    at org.eclipse.aether.

Answer 1

I just saw the version difference in the poms. 1.0.0 and 1.0. Check? Ohh you updated the same :)

Answer 2

Amid so many details to track I made the following mistake:

The parent version was listed as 1.0 . The actual version in the parent pom.xml is 1.0.0.

There was no conceptual misunderstanding on my part: just attention to detail.

Answer 3

The primary answer to this should be at When maven says "resolution will not be reattempted until the update interval of MyRepo has elapsed", where is that interval specified? I am guessing you might have tried an incorrect relativePath while building the project at some stage and that tried generating the artifact and failed but now that pom.xml is cached with an incorrect relativePath and would keep on throwing an error.

Would also suggest you go through this answer at How do you clear Apache Maven's cache? to use an effective way of clearing the cache if you simply don't want to delete the repository

More about <relativePath>, and it's use -

The relative path of the parent <code>pom.xml</code> file within the checkout.

The default value is ../pom.xml.

Maven looks for the parent pom first in the reactor of currently building projects, then in this location on the filesystem, then the local repository, and lastly in the remote repo.

<code>relativePath</code> allows you to select a different location, for example when your structure is flat, or deeper without an intermediate parent pom.

However, the group ID, artifact ID and version are still required, and must match the file in the location given or it will revert to the repository for the POM.

This feature is only for enhancing the development in a local checkout of that project.

In your case, the structure as depicted from the question doesn't need to explicitly define the relativePath and can use its default value skipping its declaration.