脱机/断开连接时，如何让Ivy从本地缓存解析依赖项（包括与changing="true"的依赖项）？
我正在做一个基于Java的开源项目，该项目使用ApacheIvy来解析和下载第三方依赖关系。该项目的build.xml有一个名为resolve的ant目标，它下载Ivy（如果需要），然后使用Ivy检索所需的jar。
在线时一切都很好。但是，如果没有Internet访问，即使所需的jar在本地Ivy缓存（~/.ivy2/cache）中，ant resolve也会失败。Ivy似乎正在尝试连接到Maven存储库以刷新changing="true"依赖关系。
我得到的错误类似于以下内容：
[ivy:retrieve] You probably access the destination server through a proxy server that is not well configured.
[ivy:retrieve] You probably access the destination server through a proxy server that is not well configured.
[ivy:retrieve]
[ivy:retrieve] :: problems summary ::
[ivy:retrieve] :::: WARNINGS
[ivy:retrieve] Host repo.example.com not found. url=http://repo.example.com/exampleorg/examplename/examplerev/ivys/ivy.xml
[ivy:retrieve] Host repo.example.com not found. url=http://repo.example.com/exampleorg/examplename/examplerev/jars/examplename.jar
[ivy:retrieve] module not found: exampleorg#examplename;examplerev
[ivy:retrieve] ==== local: tried
[ivy:retrieve] ~/.ivy2/local/exampleorg/examplename/examplerev/ivys/ivy.xml
[ivy:retrieve] -- artifact exampleorg#examplename;examplerev!examplename.jar:
[ivy:retrieve] ~/.ivy2/local/exampleorg/examplename/examplerev/jars/examplename.jar
[ivy:retrieve] ==== shared: tried
[ivy:retrieve] ~/.ivy2/shared/exampleorg/examplename/examplerev/ivys/ivy.xml
[ivy:retrieve] -- artifact exampleorg#examplename;examplerev!examplename.jar:
[ivy:retrieve] ~/.ivy2/shared/exampleorg/examplename/examplerev/jars/examplename.jar
[ivy:retrieve] ==== repo: tried
[ivy:retrieve] http://repo.example.com/exampleorg/examplename/examplerev/ivys/ivy.xml
[ivy:retrieve] -- artifact exampleorg#examplename;examplerev!examplename.jar:
[ivy:retrieve] http://repo.example.com/exampleorg/examplename/examplerev/jars/examplename.jar
[ivy:retrieve] ::::::::::::::::::::::::::::::::::::::::::::::
[ivy:retrieve] :: UNRESOLVED DEPENDENCIES ::
[ivy:retrieve] ::::::::::::::::::::::::::::::::::::::::::::::
[ivy:retrieve] :: exampleorg#examplename;examplerev: not found
[ivy:retrieve] ::::::::::::::::::::::::::::::::::::::::::::::
[ivy:retrieve]
[ivy:retrieve] :: USE VERBOSE OR DEBUG MESSAGE LEVEL FOR MORE DETAILS
BUILD FAILED
~/exampleproj/build.xml:123: impossible to resolve dependencies:
resolve failed - see output for details
按照警告的建议运行ant -verbose resolve会在输出中打印以下行：
[ivy:retrieve] don't use cache for exampleorg#examplename;examplerev: changing=true
如何让Ivy在脱机时从缓存中解析changing="true"依赖项，但在联机时继续查询每个构建的存储库？
oers已经回答了这个问题，但这并不明显。
尝试从命令行运行构建设置ivy.cache.ttl.default属性：
ant -Divy.cache.ttl.default=eternal build
来源：
- IVY-879
- 常春藤邮件列表