Qt for Python/GettingStarted/X11

(Page under development)

Requirements

• GCC (Linux)
• Python from https://www.python.org/downloads/ (Python 3.6 or Python 2.7)
• Qt 5.6+
• CLANG 3.9 (for 5.9+ branches)
• OpenSSL 1.0
• CMake from https://cmake.org/download/ (>= 3.1)
• LLVM
• virtualenv (optional but recommended)
• Python sphinx package for documentation (optional, pip install sphinx)

Building from sources

Setting up CLANG

• Download libclang, e.g.

wget http://download.qt.io/development_releases/prebuilt/libclang/libclang-release_39-linux-Rhel7.2-gcc5.3-x86_64.7z

• Extract the files, e.g.

7z x libclang-release_39-linux-Rhel7.2-gcc5.3-x86_64.7z                             

• Export the installation path to the path you choosed to place the files

export CLANG_INSTALL_DIR=$PWD/libclang                                               
                                                                                    

Getting PySide2

• Clonning the official repository

git clone --recursive https://codereview.qt-project.org/pyside/pyside-setup         

• Checking out the version that we want to build, e.g. 5.9 (Keep in mind you need to use the same version as your Qt installation)

cd pyside-setup && git checkout 5.9                                                                 

Building PySide2

• Check your Qt installation path, to specifically use that version of qmake to build PySide2:

which qmake

• Check your OpenSSL installation path, to specify it to build PySide2:

which openssl

• Build can take a few minutes, so it is recommended to use more than one CPU core (e.g. 8). Remember to replace the paths to your current qmake and openssl path:

python setup.py build --qmake=/path/to/qmake  --openssl=/path/to/openssl --build-tests --ignore-git --jobs=8
                                                                                    

Installing PySide2

• To install on the current directory, just run:

python setup.py install --qmake=/path/to/qmake  --openssl=/path/to/openssl --build-tests --ignore-git --jobs=8
                                                                                    

Test installation

• You can execute one of the examples to verify the process is properly working.
• Remember to properly set the environment variables for Qt and PySide2.

python examples/examples/widgets/widgets/tetrix.py
               

Development

Development happens in the 5.9 and dev branches of the pyside-setup repository.

The top level repository has the following submodules:

• sources/pyside2-tools: uic, rcc tools
• examples/

Contributions follow the standard process.

It is helpful to have debug binaries or symbols for Python available. Debug packages can be installed separately in some Linux distributions (e.g.: Ubuntu, the packages python3-dbg, libpython3-dbg provide a debug binary python3-dbg)

If your distribution does not include them, you can download python and compile it by yourself, e.g.

./configure --prefix=/your/installation/path  CFLAGS="-O0 -fno-inline -fno-omit-frame-pointer -g" LDFLAGS="-O0" CPPFLAGS="-O0" OPT="-O0 -g"
make
make install
                                                                                    

It is also recommended to use a Virtual Environment for testing to be able to always start from a clean base and avoid issues with write permissions in installations.

A new virtual environment can be created as follows:

virtualenv -p /usr/bin/python3-dbg testenv                                          

Please take into consideration that the binary name might be different in your system, and that you can choose a different name for the environment instead of testenv.

Troubleshooting

• Wrong RUNPATH

If the RUNPATH is wrongly setted in your Python (virtual environment), and it is pointing to the system instead of your local installation, you can patch it with a binary that PySide2 provide:

cd pyside-setup
./patchelf --set-rpath /path/to/your/local/python/lib /path/to/your/python/virtualenv/binary/python

And then proceed to re-install PySide2. (you can check if the patch worked with readelf -d /path/to/your/python/virtualenv/binary/python)

• Missing libICU cause linking problems

From 5.9+ you can get a copy of libICU specifying --standalone (but not including --iculib-url) as an argument to setup.py execution.