gentoo-overlay/dev-lua/luarocks/metadata.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE pkgmetadata SYSTEM "http://www.gentoo.org/dtd/metadata.dtd">
<pkgmetadata>
  <!-- maintainer-needed -->
  <use>
    <flag name="curl">Uses <pkg>net-misc/curl</pkg> for fetching lua
      packages instead of <pkg>net-misc/wget</pkg>.</flag>
    <flag name="openssl">Uses <pkg>dev-libs/openssl</pkg> for verifying lua
      packages instead of md5sum.</flag>
  </use>
</pkgmetadata>