code: def scan(node, env, libpath = ()):
      try:
          libs = env['LIBS']
      except KeyError:
          return []
      libs = _subst_libs(env, libs)
      try:
          prefix = env['LIBPREFIXES']
          if not SCons.Util.is_List(prefix):
              prefix = [ prefix ]
      except KeyError:
          prefix = [ '' ]
      try:
          suffix = env['LIBSUFFIXES']
          if not SCons.Util.is_List(suffix):
              suffix = [ suffix ]
      except KeyError:
          suffix = [ '' ]
      pairs = []
      for suf in map(env.subst, suffix):
          for pref in map(env.subst, prefix):
              pairs.append((pref, suf))
      result = []
      if callable(libpath):
          libpath = libpath()
      find_file = SCons.Node.FS.find_file
      adjustixes = SCons.Util.adjustixes
      for lib in libs:
          if SCons.Util.is_String(lib):
              for pref, suf in pairs:
                  l = adjustixes(lib, pref, suf)
                  l = find_file(l, libpath, verbose=print_find_libs)
                  if l:
                      result.append(l)
          else:
              result.append(lib)
      return result