Migration to Python3

Current official PyBitmessage is written in Python2 and runs with PyQt4. Both of Python2 and PyQt4 are obsolete, so migration to recent versions is highly desirable. But official developers does not release new versions for past long years. I wondered what were the core obstacles which prevent to upgrade, so I began trying to port the official PyBitmessage to Python3 as an unofficial private research project.

I'm using Devuan GNU+Linux Daedalus which is almost compatible to Debian GNU/Linux bookworm except systemd related elements. Python2 is already dropped from Debian packages, so I have to use Python3 for the research project anyway. I found there are Qt6 packages already, so I decided to use PyQt6 from Debian packages.

I modified the launcher script "start.sh" to use Python3, and executed it. Some messages were printed saying that PyBitmessage does not support Python3, and the program was terminated. So I removed the version check code, and retried. Then some errors were printed which may due to incompatibilities between Python3 and Python2. I tried to resolve errors heuristically by minimal abrupt ad hoc modifications. I also replaced PyQt4 with PyQt6, so many formal changes were required.

The road seemed to be very long and no goals were in sight. I thought that I would give up soon, but I had plenty of time to kill, so I continued the job as a hobby. Then, by three days of work, an unofficial dirty version of PyBitmessage which seemed to be running with Python3 and PyQt6 in some degree had been created. The dirty version was not tested almost at all, and it shall contain many many bugs anyway, but it launched with partially broken main window and it was able to send and receive some messages.

I had pushed a pull request abruptly to the official PyBitmessage repository at GitHub. I never thought it should be merged to mainline. It might be a kind of message, possibly a love letter. Love has many forms.