{
  lib,
  fromElisp,
}: prefixUrl:
with builtins;
  lib.pipe (fetchurl (prefixUrl + "archive-contents")) [
    readFile
    fromElisp.fromElisp
    head
    # I don't understand the exact format of the package archives.
    # I don't know why the first element is 1, but I'll just drop it.
    tail
    (map (xs: {
      name = head xs;
      value = tail xs;
    }))
    listToAttrs
  ]
