class SassC::SyntaxError

def backtrace 

def backtrace
  return nil if super.nil?
  sass_backtrace + super
end

def initialize(message, filename: nil, line: nil) 

def initialize(message, filename: nil, line: nil)
  @filename = filename
  @line = line
  super(message)
end

def sass_backtrace

The backtrace of the error within Sass files. 
def sass_backtrace
  return [] unless @filename && @line
  ["#{@filename}:#{@line}"]
end