also had another (minor) discussion topic as I was looking into `rescue nil` and friends : 
does it make sense for a provided back-trace (non-empty or nil) to still capture a stack-trace? 
... case like `raise SomeError, 'failed', ex.backtrace`

currently I do see a value in logging the 'captured' trace (-Xlog.backtraces) but since its provided I am not sure its to be expected