Troubleshooting
###############

There are many different issues that can arise when setting up Looking
Glass. Below is a list of known issues with potential solutions:

.. _when_launching_looking_glass_the_desktop_doesnt_appear:

When Launching Looking Glass the Desktop Doesn't Appear
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

-  **Using an AMD GPU?**

   -  After the end of the Radeon HD Series, new AMD GPUs go to sleep when no
      display is connected. For this reason, one of two conditions must be met.

#. The GPU needs to remain plugged into a monitor (this is good for
   testing & troubleshooting).
#. The GPU needs to have a dummy plug installed which presents itself as a
   monitor.

.. _the_clipboard_is_not_working:

The Clipboard is not Working
~~~~~~~~~~~~~~~~~~~~~~~~~~~~

-  **Is clipboard synchronization enabled?**

   -  Before you can copy or paste content between the Guest and Host,
      :ref:`clipboard
      synchronization <how_to_enable_clipboard_synchronization_via_spice>`
      must be enabled.

-  **Did you install the Spice Guest Tools?**

   -  The `SPICE Guest Tools
      driver <https://www.spice-space.org/download.html>`_ must be installed
      on the host OS to synchronize the clipboard.
      The download is labeled "spice-guest-tools".

      .. warning::

         Do **NOT** install the QEMU Guest Tools driver.
         These are not the same.

   -  **Is it installed twice?**

      -  The Spice VDAgent is available in both Spice Guest Tools, and
         standalone as a separate installer. Check your installed programs
         and uninstall the VDAgent if it's installed separately.

.. _followed_installation_instructions_but_looking_glass_still_doesnt_launch:

Followed Installation Instructions but Looking Glass Still Doesn't Launch
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Depending on your distribution, various circumstances can cause Looking
Glass to still not run. Below is a list of known issues that can prevent
Looking Glass from running properly.

AppArmor
^^^^^^^^

AppArmor is a security application that can prevent Looking Glass from
running. How to add security exceptions may vary on your distribution:

Start by opening the file ``/etc/apparmor.d/abstractions/libvirt-qemu``.
Now locate and edit the following lines to represent how they appear in
the example:

.. code:: text

   # for usb access
      /dev/bus/usb/** rw,
      /etc/udev/udev.conf r,
      /sys/bus/ r,
      /sys/class/ r,
      /run/udev/data/* rw,
      /dev/input/* rw,

   # Looking Glass
      /dev/shm/looking-glass rw,

Save, exit, and restart AppArmor:

.. code:: text

   sudo systemctl restart apparmor