I noticed that I can reliably crash WebKit Nightly builds when I enable the console with command-alt-c and then switch tot he debugger view (thereby enabling the debugger) during loading of a js heavy page.
Some Crashlogs appended
Created attachment 77982 [details]
Created attachment 77984 [details]
video of how to trigger the crash
This is a SproutCore application, (like mobile me)
Closing as invalid, as this bug pertains to the old inspector UI and/or its tests.
Please file a new bug (https://www.webkit.org/new-inspector-bug) if the bug/feature/issue is still relevant to WebKit trunk.