[INFO] --- features-maven-plugin:2.1.99-SNAPSHOT:add-features-to-repo (add-features-to-repo) @ apache-karaf ---
[INFO] Base repo: file:///home/pieber/.m2/repository/
[INFO] Copying bundle: mvn:org.apache.sshd/sshd-core/0.5.0
[INFO] Copying bundle: mvn:org.apache.mina/mina-core/2.0.1
        
Downloading: http://svn.apache.org/repos/asf/servicemix/m2-repo/org/apache/mina/mina-core/2.0.1
        /mina-core-2.0.1
        .jar
Downloading: http://uk.maven.org/maven2/org/apache/mina/mina-core/2.0.1
        /mina-core-2.0.1
        .jar
[ERROR] Can't resolve bundle mvn:org.apache.mina/mina-core/2.0.1
        
org.apache.maven.artifact.resolver.ArtifactNotFoundException: Could not find artifact org.apache.mina:mina-core:jar:2.0.1
         in servicemix (http://svn.apache.org/repos/asf/servicemix/m2-repo)

Try downloading the file manually from the project website.

Then, install it using the command: 
    mvn install:install-file -DgroupId=org.apache.mina -DartifactId=mina-core -Dversion=2.0.1
         -Dpackaging=jar -Dfile=/path/to/file

Alternatively, if you host your own repository you can deploy the file there: 
    mvn deploy:deploy-file -DgroupId=org.apache.mina -DartifactId=mina-core -Dversion=2.0.1
         -Dpackaging=jar -Dfile=/path/to/file -Durl=[url] -DrepositoryId=[id]


  org.apache.mina:mina-core:jar:2.0.1
        

from the specified remote repositories:
  apache-snapshots (http://repository.apache.org/content/groups/snapshots-group, releases=false, snapshots=true),
  servicemix (http://svn.apache.org/repos/asf/servicemix/m2-repo, releases=true, snapshots=false),
  sonatype (http://repository.sonatype.org/content/groups/sonatype-public-grid, releases=false, snapshots=true),
  fusesource.snapshots (http://repo.fusesource.com/nexus/content/repositories/snapshots, releases=false, snapshots=true),
  apache.snapshots (http://repository.apache.org/snapshots, releases=false, snapshots=true),
  uk (http://uk.maven.org/maven2/, releases=true, snapshots=false)

        at org.apache.maven.artifact.resolver.DefaultArtifactResolver.resolve(DefaultArtifactResolver.java:235)
        at org.apache.maven.artifact.resolver.DefaultArtifactResolver.resolve(DefaultArtifactResolver.java:173)
        at org.apache.maven.artifact.resolver.DefaultArtifactResolver.resolve(DefaultArtifactResolver.java:541)
        at org.apache.karaf.tooling.features.AddFeaturesToRepoMojo.execute(AddFeaturesToRepoMojo.java:152)
        at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:107)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:195)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:148)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:140)
        at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:84)
        at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:59)
        at org.apache.maven.lifecycle.internal.LifecycleStarter.singleThreadedBuild(LifecycleStarter.java:183)
        at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:161)
        at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:316)
        at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:153)
        at org.apache.maven.cli.MavenCli.execute(MavenCli.java:451)
        at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:188)
        at org.apache.maven.cli.MavenCli.main(MavenCli.java:134)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:290)
        at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:230)
        at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:409)
        at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:352)
Caused by: org.sonatype.aether.resolution.ArtifactResolutionException: Could not find artifact org.apache.mina:mina-core:jar:2.0.1
         in servicemix (http://svn.apache.org/repos/asf/servicemix/m2-repo)
        at org.sonatype.aether.impl.internal.DefaultArtifactResolver.resolveArtifacts(DefaultArtifactResolver.java:499)
        at org.sonatype.aether.impl.internal.DefaultArtifactResolver.resolveArtifact(DefaultArtifactResolver.java:187)
        at org.sonatype.aether.impl.internal.DefaultRepositorySystem.resolveArtifact(DefaultRepositorySystem.java:245)
        at org.apache.maven.artifact.resolver.DefaultArtifactResolver.resolve(DefaultArtifactResolver.java:229)
        ... 24 more
Caused by: org.sonatype.aether.transfer.ArtifactNotFoundException: Could not find artifact org.apache.mina:mina-core:jar:2.0.1
         in servicemix (http://svn.apache.org/repos/asf/servicemix/m2-repo)
        at org.sonatype.aether.connector.wagon.WagonRepositoryConnector$4.wrap(WagonRepositoryConnector.java:930)
        at org.sonatype.aether.connector.wagon.WagonRepositoryConnector$4.wrap(WagonRepositoryConnector.java:925)
        at org.sonatype.aether.connector.wagon.WagonRepositoryConnector$GetTask.flush(WagonRepositoryConnector.java:681)
        at org.sonatype.aether.connector.wagon.WagonRepositoryConnector$GetTask.flush(WagonRepositoryConnector.java:675)
        at org.sonatype.aether.connector.wagon.WagonRepositoryConnector.get(WagonRepositoryConnector.java:420)
        at org.sonatype.aether.impl.internal.DefaultArtifactResolver.resolveArtifacts(DefaultArtifactResolver.java:411)
        ... 27 more