Can't download project dependency (db4o) from Maven: cert error

I have a Maven project and added db4o as a dependency using this answer from a previous question. When I compile the project it gives me the following error:

Could not resolve dependencies for project org.uca.dss:trenes:jar:1.0-SNAPSHOT: [...] Failed to read artifact descriptor for com.db4o:db4o-full-java5:jar:7.13-SNAPSHOT: Could not transfer artifact com.db4o:db4o-full-java5:pom:7.13-SNAPSHOT from/to source.db4o (https://source.db4o.com/maven/): Error transferring file: sun.security.validator.ValidatorE开发者_如何转开发xception: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target -> [Help 1]

Curiously enough, it only happens in Ubuntu GNU/Linux (tested in two PC's), but not in Windows (using NetBeans 7.0).

I can post the full error (from maven -X output), but I think it does not add much information

Edit 1: This is what I have in my pom.xml file regarding db4o:

<repository>
  <id>source.db4o</id>
  <url>https://source.db4o.com/maven/</url>
</repository>
...
<dependency>
    <groupId>com.db4o</groupId>
    <artifactId>db4o-full-java5</artifactId>
    <version>7.13-SNAPSHOT</version>
</dependency>

This looks like a security certificate issue for a secured request which is generally looked up from %JAVA_HOME%\jre\lib\security\cacerts . I am guessing your windows JRE has the entries whereas the ubuntu JRE is lacking them.

By the way this link is a good read on installing certs. You probably want to use the option 1 mentioned there.