One call to console.profile() followed by console.profileEnd() seems to work fine. When I started a second profile, I accidentally had it followed with console.endProfile(), which was causing a crash. I can't reproduce with a simple test case, but here's the crash report. Hope its helpful. http://paste.lisp.org/display/67514
<rdar://problem/6252646>
The crash log is now gone so there isn't anything actionable here. However, the new sampling profiler completely changes the vast majority of code that runs when console.profile/profileEnd are used. Very little, if anything, remains of what did in 2008 =). Closing.