SystemStackError Backtrace returns String not Array
In this commit http://github.com/shyouhei/ruby/commit/ecd11fb371b5f4a00d0b0006b325de3c5437b8d2 changes were introduced that affected how SystemStackError's backtrace was handled. The changes resulted in SystemStackError's backtrace returning a String instead of an Array. However, previously all backtraces have been Arrays. All available documentation supports this notion and numerous Ruby project, including Rails have relied on the backtrace being an Array. Even if the backtrace is going to be truncated as a single line, it should still be returned as a single element Array.