启动eclipse时界面一闪而过，用命令启动，可以看到报错：
Jobs should be canceled by the plugin that scheduled them during shutdown: org.eclipse.epp.internal.mpc.ui.wizards.MarketplaceDropAdapter
这是上次eclipse异常退出造成的，解决方法：
$ rm YOUR_WORKSPACE_DIR/.metadata/.plugins/org.eclipse.e4.workbench/workbench.xmi