title: What does this eclipse error mean: "path for project must have only one segment"?
body: <p>There are a couple very similar questions here, except they are related to Android run/debug configurations. I'm trying to configure a GWT app. I get this error when I try to save a change in the properties. Specifically, in the project properties UI, I'm in Google->Web Application, and I'm trying to uncheck 'Launch and deploy from this directory'. I have 'This project has a WAR directory' property checked, and a valid folder in the "WAR directory" box.</p>
  
  <p>The error says to check the eclipse error log for more details, so I did, but not much helpful there. Here's the top few lines from the stack trace there : </p>
  
  <pre><code>java.lang.IllegalArgumentException: Path for project must have only one segment.
  at org.eclipse.core.runtime.Assert.isLegal(Assert.java:63)
  at org.eclipse.core.internal.resources.WorkspaceRoot.getProject(WorkspaceRoot.java:183)
  at org.eclipse.jdt.internal.core.JavaModel.getJavaProject(JavaModel.java:189)
  at org.eclipse.jdt.launching.JavaRuntime.getJavaProject(JavaRuntime.java:1229)
  at com.google.gdt.eclipse.core.launch.LaunchConfigurationUtilities.getJavaProject(LaunchConfigurationUtilities.java:83)
  at com.google.gdt.eclipse.core.launch.LaunchConfigurationUtilities.getLaunchConfigurations(LaunchConfigurationUtilities.java:102)
  at com.google.gdt.eclipse.suite.launch.processors.LaunchConfigAffectingChangesListener.updateLaunchConfigs(LaunchConfigAffectingChangesListener.java:248)
  at com.google.gdt.eclipse.suite.launch.processors.LaunchConfigAffectingChangesListener.updateLaunchConfigurations(LaunchConfigAffectingChangesListener.java:238)
  at com.google.gdt.eclipse.suite.launch.processors.LaunchConfigAffectingChangesListener.warOutLocationChanged(LaunchConfigAffectingChangesListener.java:243)
  at com.google.gdt.eclipse.core.properties.WebAppProjectProperties.notifyWarOutLocationChangedListeners(WebAppProjectProperties.java:236)
  at com.google.gdt.eclipse.core.properties.WebAppProjectProperties.setWarSrcDir(WebAppProjectProperties.java:208)
  at com.google.gdt.eclipse.core.properties.ui.WebappProjectPropertyPage.saveProjectProperties(WebappProjectPropertyPage.java:216)
  at com.google.gdt.eclipse.core.ui.AbstractProjectPropertyPage.performOk(AbstractProjectPropertyPage.java:77)
  </code></pre>
  
  <p>My workspace path has no spaces; it is C:\projects\eclipse\workspaces\MyProjectHasNoSpaces</p>
  
  <p>I'm running eclipse Helios; GWT 2.5, java 1.6.0_45, Windows 7, 64-bit.</p>