title: Installation of gcc-aarch64-linux-gnu in ubuntu bionic on armhf cpu fails
body: <p>I am trying to install g++-aarch64-linux-gnu and gcc-aarch64-linux-gnu under ubuntu 18.04, using the command </p>
  
  <pre><code>sudo apt install g++-aarch64-linux-gnu gcc-aarch64-linux-gnu
  </code></pre>
  
  <p>However I get this error message:</p>
  
  <blockquote>
    <p>Package gcc-aarch64-linux-gnu is not available, but is referred to by
    another package. This may mean that the package is missing, has been
    obsoleted, or is only available from another source</p>
    
    <p>Package g++-aarch64-linux-gnu is not available, but is referred to by
    another package. This may mean that the package is missing, has been
    obsoleted, or is only available from another source</p>
    
    <p>E: Package 'g++-aarch64-linux-gnu' has no installation candidate E:
    Package 'gcc-aarch64-linux-gnu' has no installation candidate</p>
  </blockquote>
  
  <p>My <code>/etc/apt/sources.list</code> contains</p>
  
  <blockquote>
    <p>deb <a href="http://ports.ubuntu.com/ubuntu-ports" rel="nofollow noreferrer">http://ports.ubuntu.com/ubuntu-ports</a> bionic main universe deb
    <a href="http://ports.ubuntu.com/ubuntu-ports" rel="nofollow noreferrer">http://ports.ubuntu.com/ubuntu-ports</a> bionic-updates main universe deb
    <a href="http://ports.ubuntu.com/ubuntu-ports" rel="nofollow noreferrer">http://ports.ubuntu.com/ubuntu-ports</a> bionic-security main universe</p>
  </blockquote>
  
  <p>I would be glad if somebody could help me with this (:</p>