This update was merged with a33b9a8, which has the `--disable-threads`
flag. This update brings support for `x86_64` and uses a more up to date
Github url. It also removes the `workdir` as it was set to the default.
We may need entries with spaces in makeopts, installopts, and
configopts, and at that point we should also convert depends and
auth_opts to avoid confusion.