.. _designer_pyqt515_issue:

Troubleshoot Taurus widgets in Qt Designer
==========================================

Missing Taurus widgets with Conda and PyQt5 >= 5.15.4
-----------------------------------------------------

When launching ``taurus designer``, Taurus widgets may not appear in Qt
Designer in Conda environments using PyQt5 5.15.4 or newer.

The documented cause is that the conda-forge build may not provide the
``libpyqt5.so`` library required for loading external Designer plugins. See the
`conda-forge issue <https://github.com/conda-forge/pyqt-feedstock/issues/113>`_
for context.

Two workarounds are available.

Use a dedicated Designer environment
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Create or use a Conda environment with PyQt5 5.12 specifically for running
Qt Designer.

Copy ``libpyqt5.so`` into the environment
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Copy ``libpyqt5.so`` to::

    /path/to/conda/envs/<env_name>/plugins/designer/

The file can be obtained from either:

- another Conda environment with PyQt5 5.12, from the same
  ``plugins/designer`` directory; or
- a system PyQt5 installation, typically from
  ``/usr/lib/x86_64-linux-gnu/qt5/plugins/designer/`` on Linux.

Ensure that the Python version of the source environment matches the Python
version of the destination environment.

For the normal Designer workflow, see :doc:`../tutorials/designer`.