Another thing to add to the list of "Life is too short".

Attempted to add an SVN project from http://code.google.com/p/project into Eclipse using the SVN plugin. Project is an android project.

Total failure. Eventually I got down to errors like:

java.lang.IllegalArgumentException: Path must include project and resource name: /android-l2tp-tether
        at org.eclipse.core.runtime.Assert.isLegal(Assert.java:63)
        at org.eclipse.core.internal.resources.Workspace.newResource(Workspace.java:1628)
        at org.eclipse.core.internal.resources.Container.getFolder(Container.java:137)
        at com.android.ide.eclipse.adt.internal.build.PreCompilerBuilder.buildAidlCompilationList(Unknown Source)
        at com.android.ide.eclipse.adt.internal.build.PreCompilerBuilder.build(Unknown Source)

Noting that there were a project called 'android-l2tp-tether'...
Eclipse is just too big, too clumsy, and too opaque to usefully debug. I wasted an hour wandering around with straces et al, but realized I was just wasting time. Copying the svn directory else, and then doing 'create new project from existing source' was instantly successful. ugh.