我正在尝试按照此站点上的说明进行操作：
http://trac.erichseifert.de/warp/wiki/DeveloperGuide
我已经获得了所有源代码 - 并且在 mpqparser 和 vectorgraphics2d 上都完成了 mvn install - 然后我进入 gral 文件夹 - 并尝试运行它，我遇到了这个错误：
> $ mvn install
[INFO] Scanning for projects...
[WARNING]
[WARNING] Some problems were encountered while building the effective model for
de.erichseifert.gral:GRAL:jar:0.8
[WARNING] 'reporting.plugins.plugin.version' for org.apache.maven.plugins:maven-
changelog-plugin is missing. @ line 143, column 17
[WARNING]
[WARNING] It is highly recommended to fix these problems because they threaten t
he stability of your build.
[WARNING]
[WARNING] For this reason, future Maven versions might no longer support buildin
g such malformed projects.
[WARNING]
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building GRAL Graphing Library 0.8
[INFO] ------------------------------------------------------------------------
[WARNING] The POM for de.erichseifert.vectorgraphics2d:VectorGraphics2D:jar:0.6
is missing, no dependency information available
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 0.329s
[INFO] Finished at: Sun Apr 22 00:18:13 BST 2012
[INFO] Final Memory: 3M/122M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal on project GRAL: Could not resolve dependencies f
or project de.erichseifert.gral:GRAL:jar:0.8: Failure to find de.erichseifert.ve
ctorgraphics2d:VectorGraphics2D:jar:0.6 in http://repo.maven.apache.org/maven2 w
as cached in the local repository, resolution will not be reattempted until the
update interval of central has elapsed or updates are forced -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e swit
ch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please rea
d the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/DependencyReso
lutionException
我认为它正在尝试加载刚刚在 vectorgraphics2D 文件夹中构建的 jar - 但我不确定 wiki 说明是否缺少步骤，或者是否需要设置某些内容。
gral 的 pom.xml 具有以下作为其依赖关系的声明：
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.8.1</version>
<scope>test</scope>
<optional>true</optional>
</dependency>
<dependency>
<groupId>de.erichseifert.vectorgraphics2d</groupId>
<artifactId>VectorGraphics2D</artifactId>
<version>0.6</version>
<optional>true</optional>
</dependency>
</dependencies>
请有人可以帮助我解决这个问题 - 这是我第一次体验 Maven！