gentoo-overlay/app-crypt/libu2f-host/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="systemd">
      Use user ACLs rather than plugdev group to give user access to the HIDRAW
      device.
    </flag>
  </use>
  <upstream>
    <remote-id type="github">Yubico/libu2f-host</remote-id>
    <bugs-to>https://github.com/Yubico/libu2f-host/issues</bugs-to>
  </upstream>
</pkgmetadata>