old_contents: from os.path import dirname
  from django.conf import settings
  
  from pipeline.compilers import SubProcessCompiler
  
  class CompassCompiler(SubProcessCompiler):
      output_extension = 'css'
  
      def match_file(self, filename):
          return filename.endswith(('.scss', '.sass'))
  
      def compile_file(self, infile, outfile, outdated=False, force=False):
          command = "%s compile --boring --sass-dir=%s --css-dir=%s %s %s 1>&2" % (
              getattr(settings, 'PIPELINE_COMPASS_BINARY', '/usr/bin/env compass'),
              dirname(infile),
              dirname(outfile),
              getattr(settings, 'PIPELINE_COMPASS_ARGUMENTS', ''),
              infile
          )
          return self.execute_command(command, cwd=dirname(infile))
new_contents: from os.path import dirname
  from django.conf import settings
  
  from pipeline.compilers import SubProcessCompiler
  
  class CompassCompiler(SubProcessCompiler):
      output_extension = 'css'
  
      def match_file(self, filename):
          return filename.endswith(('.scss', '.sass'))
  
      def compile_file(self, infile, outfile, outdated=False, force=False):
          if not outdated and not force:
              return
          command = "%s compile --boring --sass-dir=%s --css-dir=%s %s %s" % (
              getattr(settings, 'PIPELINE_COMPASS_BINARY', '/usr/bin/env compass'),
              dirname(infile),
              dirname(outfile),
              getattr(settings, 'PIPELINE_COMPASS_ARGUMENTS', ''),
              infile
          )
          return self.execute_command(command, cwd=dirname(infile))
  
subject: fix error detection (new django-pipline uses stderr for that)