gentoo-overlay/app-arch/zstd/metadata.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE pkgmetadata SYSTEM "http://www.gentoo.org/dtd/metadata.dtd">
<pkgmetadata>
  <maintainer type="person">
    <email>patrick@gentoo.org</email>
    <name>Patrick Lauer</name>
  </maintainer>
  <use>
    <flag name="lz4">
      Enable support for LZ4 compression using <pkg>app-arch/lz4</pkg>
    </flag>
  </use>
  <upstream>
    <remote-id type="github">facebook/zstd</remote-id>
  </upstream>
</pkgmetadata>