看到所有其他答案。我找到了一个更简单的方法。

我只是删除了.classpath(用eclipse编辑)中包含var的所有行，并使用maven ->更新项目而没有出现错误。

右键单击项目，选择Maven -> Remove Maven Nature。 打开你的终端，进入你的项目文件夹，执行mvn eclipse:clean 右键单击您的项目，选择“配置->转换为Maven项目”

现在你的“Unsupported IClasspathEntry kind=4 Eclipse Scala”消失了。

这个问题(https://bugs.eclipse.org/394042)在m2e 1.5.0中得到修复，该版本可用于Eclipse Kepler和Luna:

http://download.eclipse.org/technology/m2e/releases/1.5

如果你也使用m2e-wtp，你还需要安装m2e-wtp 1.1.0:

http://download.eclipse.org/m2e-wtp/releases/luna/1.1

我无法让mvn eclipse:clean等与开普勒一起工作。

然而，我改变了创建和扩展变量，只使用eclipse类路径中的外部jar。这反映在我的.classpath中没有var。

这纠正了问题。我更新了Maven。

有时，即使重新导入Maven项目也无法工作。在eclipse中正确地更新项目并不是一个确定的过程。 我发现的唯一100%安全的程序是:

Disable Maven Nature, run mvn eclipse:clean, restart, cross your fingers and Pray 3 times. If this won't work, delete the project, run mvn eclipse:clean, re-import refresh, pray and use the force. If this still doesn't work, restart Eclipse, or even better your computer. While waiting for the reboot, you can make a random donation to fix your Karma. Repeat step 2 and don't forget to pray and control your anger. Anger leads to hate. Hate leads to suffering. Try all the other answers posted in this thread. You might need to try them all for 3 times at least before giving up. Format your Computer, re-install Eclipse and Maven. No need to pray anymore, all gods hate you anyway Delete your git project, burn the physical drive that stored the remote repository, and write your project from scratch. Find a time machine, travel to the past and convince yourself to follow another, non-programming career or at least to avoid Java

I tried Marco's steps but no luck. Instead if you just get the latest m2e plugin from the link he provides and one by one right click on each project -> Maven -> Update Dependencies the error still pops up but the issue is resolved. That is to say the warnings disappear in the Markers view. I encountered this issue after importing some projects into SpringSource Tool Suite (STS). When I returned to my Eclipse Juno installation the warnings were displaying. Seeing that I had m2e 1.1 already installed I tried Marco's steps to no avail. Getting the latest version fixed it however.