code: def _detect_msgmerge(env):
      
      if 'MSGMERGE' in env:
          return env['MSGMERGE']
      msgmerge = env.Detect('msgmerge');
      if msgmerge:
          return msgmerge
      raise SCons.Errors.StopError(MsgmergeNotFound, "Could not detect msgmerge")
      return None
docs: Detects *msgmerge(1)* program.