title: Maven project - server error 500 for me but works fine for someone else
body: <p>I have checked out a maven project which gives me a "<code>Return code is: 500, ReasonPhrase:Internal Server Error.</code>" when I try to compile it. Strangely though for a colleague exactly the same is working without problems. What can I do here?</p>
  
  <p><strong>My Maven output</strong></p>
  
  <pre><code>autosparql-lite$ mvn clean compile
  [INFO] Scanning for projects...
  [INFO]                                                                         
  [INFO] ------------------------------------------------------------------------
  [INFO] Building AutoSPARQL Lite 1.0-SNAPSHOT
  [INFO] ------------------------------------------------------------------------
  Downloading: http://uk.maven.org/maven2/org/apache/maven/plugins/maven-clean-plugin/2.4.1/maven-clean-plugin-2.4.1.pom
  Downloaded: http://uk.maven.org/maven2/org/apache/maven/plugins/maven-clean-plugin/2.4.1/maven-clean-plugin-2.4.1.pom (5 KB at 9.4 KB/sec)
  Downloading: http://uk.maven.org/maven2/org/apache/maven/plugins/maven-clean-plugin/2.4.1/maven-clean-plugin-2.4.1.jar
  Downloaded: http://uk.maven.org/maven2/org/apache/maven/plugins/maven-clean-plugin/2.4.1/maven-clean-plugin-2.4.1.jar (23 KB at 57.3 KB/sec)
  Downloading: http://s1.semanticscience.org:8080/nexus/content/groups/public/com/extjs/gxt/2.2.5/gxt-2.2.5.pom
  Downloading: http://s1.semanticscience.org:8080/nexus/content/groups/public/uk/ac/shef/wit/simmetrics/1.6.2/simmetrics-1.6.2.pom
  Downloading: http://s1.semanticscience.org:8080/nexus/content/groups/public/woodstox/wstx-api/3.2.0/wstx-api-3.2.0.pom
  [INFO] ------------------------------------------------------------------------
  [INFO] BUILD FAILURE
  [INFO] ------------------------------------------------------------------------
  [INFO] Total time: 4.091s
  [INFO] Finished at: Thu Apr 12 15:45:28 CEST 2012
  [INFO] Final Memory: 14M/209M
  [INFO] ------------------------------------------------------------------------
  [ERROR] Failed to execute goal on project autosparql-lite: 
  Could not resolve dependencies for project org.dllearner:autosparql-lite:war:1.0-SNAPSHOT: 
  Failed to collect dependencies for [com.google.gwt:gwt-servlet:jar:2.3.0 (compile), com.google.gwt:gwt-user:jar:2.3.0 (provided), net.sf.ehcache:ehcache:pom:2.5.0 (compile), junit:junit:jar:4.8.1 (test), com.extjs:gxt:jar:2.2.5 (compile), org.dllearner:components-ext:jar:1.0-SNAPSHOT (compile), commons-configuration:commons-configuration:jar:1.6 (compile)]: 
  Failed to read artifact descriptor for com.extjs:gxt:jar:2.2.5: 
  Could not transfer artifact com.extjs:gxt:pom:2.2.5 from/to semanticscience.org (http://s1.semanticscience.org:8080/nexus/content/groups/public/): 
  Failed to transfer file: http://s1.semanticscience.org:8080/nexus/content/groups/public/com/extjs/gxt/2.2.5    /gxt-2.2.5.pom. Return code is: 500, ReasonPhrase:Internal Server Error. -&gt; [Help 1]
  </code></pre>
  
  <p><strong>My settings.xml</strong></p>
  
  <pre><code>&lt;settings&gt;
     &lt;mirrors&gt;
      &lt;mirror&gt;
        &lt;id&gt;UK&lt;/id&gt;
        &lt;name&gt;UK Central&lt;/name&gt;
        &lt;url&gt;http://uk.maven.org/maven2&lt;/url&gt;
        &lt;mirrorOf&gt;central&lt;/mirrorOf&gt;
      &lt;/mirror&gt;
    &lt;/mirrors&gt;
  &lt;/settings&gt;
  </code></pre>
  
  <p>P.S.:</p>
  
  <p><strong>My Maven version</strong></p>
  
  <pre><code>Apache Maven 3.0.4 (rNON-CANONICAL_2012-01-24_13-02_root; 2012-01-24 14:02:02+0100)
  Maven home: /opt/maven
  Java version: 1.7.0_03-icedtea, vendor: Oracle Corporation
  Java home: /usr/lib/jvm/java-7-openjdk/jre
  Default locale: de_DE, platform encoding: UTF-8
  OS name: "linux", version: "3.0.26-1-lts", arch: "amd64", family: "unix"
  </code></pre>
  
  <p><strong>His Maven version</strong></p>
  
  <pre><code>Apache Maven 2.2.1 (rdebian-4)
  Java version: 1.7.0
  Java home: /usr/lib/jvm/jdk1.7.0/jre
  Default locale: de_DE, platform encoding: UTF-8
  OS name: "linux" version: "2.6.38-13-generic" arch: "amd64" Family: "unix"
  </code></pre>
  
  <p>P.S.: Can it have something to do with our maven versions? I use Maven 3 and he uses Maven 2. And where does this semanticscience server come from?</p>
  
  <p>P.P.S.: Ok, I finally got rid of the semanticscience repository by deleting it from my pom.xml AND deleting the ~/.m2/repository folder. Now I get another error though, see below.</p>
  
  <p>The strange thing is that the following urls are resolvable in a browser:</p>
  
  <ul>
  <li><a href="http://repo.aduna-software.org/maven2/releases" rel="nofollow">http://repo.aduna-software.org</a></li>
  <li><a href="http://repo.aduna-software.org/maven2/releases" rel="nofollow">http://repo.aduna-software.org/maven2/releases</a></li>
  </ul>
  
  <p>However a ping does not work:</p>
  
  <pre><code>$ ping http://repo.aduna-software.org
  ping: unknown host http://repo.aduna-software.org
  $ ping http://repo.aduna-software.org/maven2/releases
  ping: unknown host http://repo.aduna-software.org/maven2/releases
  </code></pre>
  
  <p>It's not the ping's fault though:</p>
  
  <pre><code>$ ping www.google.de
  PING www-cctld.l.google.com (173.194.69.94) 56(84) bytes of data.
  64 bytes from bk-in-f94.1e100.net (173.194.69.94): icmp_req=1 ttl=48 time=13.3 ms
  [...]
  </code></pre>
  
  <p>Here is the error:</p>
  
  <pre><code>Failed to read artifact descriptor for org.openrdf.sesame:sesame-sail-memory:jar:2.4.0: Could not transfer artifact org.openrdf.sesame:sesame-sail-memory:pom:2.4.0 from/to aduna-software-release-repo (http://repo.aduna-software.org/maven2/releases): repo.aduna-software.org: Der Name oder der Dienst ist nicht bekannt: Unknown host repo.aduna-software.org: Der Name oder der Dienst ist nicht bekannt
  </code></pre>
  
  <p>I tried what <code>http://wiki.tuxtorials.de/wiki/Ping:_unknown_host</code> told me and did</p>
  
  <pre><code>echo "echo \"hosts:      files dns\" &gt; /etc/nsswitch.conf" | sudo sh
  </code></pre>
  
  <p>But that didn't help either.</p>
  
  <p>Ok I have no idea why but now it worked for me. But I would like to know why...</p>