Updating assembly plugin failed using Maven 2.0.7

[Dobri Kitipov <kd...@googlemail.com>]

Hi all,

I have an issue updating the assembly plugin from 2.2-beta-1 to
2.2-beta-2 version.
The exception thrown is the following:

OS name: "linux" version: "2.6.9-55.elsmp" arch: "i386"

     [exec] [DEBUG] Building Maven user-level plugin registry from:
'/home/buildsag/.m2/plugin-registry.xml'

     [exec] [DEBUG] Building Maven global-level plugin registry from:
'/usr/local/maven-2.0.7/conf/plugin-registry.xml'

     [exec] [INFO] Scanning for projects...

     [exec] [INFO] Searching repository for plugin with prefix: 'assembly'.

     [exec] [DEBUG] Loading plugin prefixes from group: org.apache.maven.plugins

     [exec] [INFO] org.apache.maven.plugins: checking for updates from central

     [exec] [WARNING] repository metadata for:
'org.apache.maven.plugins' could not be retrieved from repository:
central due to an error: Error transferring file

     [exec] [INFO] Repository 'central' will be blacklisted

     [exec] [DEBUG] Exception

     [exec] org.apache.maven.wagon.TransferFailedException: Error
transferring file

     [exec]      at
org.apache.maven.wagon.providers.http.LightweightHttpWagon.fillInputData(LightweightHttpWagon.java:104)

     [exec]      at org.apache.maven.wagon.StreamWagon.get(StreamWagon.java:68)

     [exec]      at
org.apache.maven.artifact.manager.DefaultWagonManager.getRemoteFile(DefaultWagonManager.java:462)

     …

     …

org.codehaus.classworlds.Launcher.mainWithExitCode(Launcher.java:430)

     [exec]      at org.codehaus.classworlds.Launcher.main(Launcher.java:375)

     [exec] Caused by: java.net.UnknownHostException: repo1.maven.org

     [exec]      at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:177)

     [exec]      at java.net.Socket.connect(Socket.java:519)

…

…

     [exec]      ... 23 more

     [exec] [DEBUG] Loading plugin prefixes from group: org.codehaus.mojo

     [exec] [DEBUG] Skipping blacklisted repository central

     [exec] [DEBUG] Skipping blacklisted repository central

     [exec] [DEBUG] maven-assembly-plugin: using locally installed snapshot

     [exec] [DEBUG] Artifact not found - using stub model: Unable to
determine the latest version

     [exec]

     [exec]   org.apache.maven.plugins:maven-assembly-plugin:pom:LATEST

     [exec]

     [exec]

     [exec] [DEBUG] Using defaults for missing POM
org.apache.maven.plugins:maven-assembly-plugin:pom:LATEST

     [exec] [DEBUG] maven-assembly-plugin: using locally installed snapshot

     [exec] [DEBUG] Artifact not found - using stub model: Unable to
determine the release version

     [exec]

     [exec]   org.apache.maven.plugins:maven-assembly-plugin:pom:RELEASE

     [exec]

     [exec]

     [exec] [DEBUG] Using defaults for missing POM
org.apache.maven.plugins:maven-assembly-plugin:pom:RELEASE

     [exec] [INFO]
------------------------------------------------------------------------

     [exec] [ERROR] BUILD ERROR

     [exec] [INFO]
------------------------------------------------------------------------

     [exec] [INFO] The plugin
'org.apache.maven.plugins:maven-assembly-plugin' does not exist or no
valid version could be found

Looking into the project's plugin repository with id="central", which is the
repository used for updates, I can find that there is a metadata file for "
org.apache.maven.plugins". Here is the definition for the assembly plugin
written into this maven-metadata-central.xml:



<plugin>

      <name>Maven Assembly Plugin</name>

      <prefix>assembly</prefix>

      <artifactId>maven-assembly-plugin</artifactId>

</plugin>



Additionally there is a maven-assembly-plugin folder with everything needed
(i.e metadata file and 2.2-beta-2 folder with the right content).

I am wondering why in this case I am receiving this exception and
particularly the line telling me:



"[WARNING] repository metadata for: 'org.apache.maven.plugins' could
not be retrieved from repository: central due to an error: Error
transferring file"

On the next line we can see:



"[exec] [INFO] Repository 'central' will be blacklisted"



My question is what can cause this error?



Things are becoming even more interesting when I read further:



"Caused by: java.net.UnknownHostException: repo1.maven.org"

I am wondering if this means that because our "central" repository is
blacklisted that is why Maven decides to associate automatically the
central repo to a default? value "repo1.maven.org"?



I am not sure if we should do something additionally when a repository is
blacklisted. Can this cause any further attempt to fail since we do not
un-blacklisted our repo somehow?

Thank you.
Best regards, Dobri