gentoo-overlay/sci-mathematics/gmp-ecm/metadata.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE pkgmetadata SYSTEM "http://www.gentoo.org/dtd/metadata.dtd">
<pkgmetadata>

  <maintainer type="person">
    <email>mjo@gentoo.org</email>
  </maintainer>

  <maintainer type="person" proxied="yes">
    <email>frp.bissey@gmail.com</email>
    <name>François Bissey</name>
  </maintainer>
  <maintainer type="project" proxied="proxy">
    <email>proxy-maint@gentoo.org</email>
    <name>Proxy Maintainers</name>
  </maintainer>

  <use>
    <flag name="custom-tune">
      Improve performance of some operations by selecting
      machine-specific defaults
    </flag>
  </use>
</pkgmetadata>