Working Palemoon build with Python3

[megastallman]

Hi guys!
I've been able to build Palemoon(as of February 27-th, 2026) on Kubuntu 25.10, purely with Python3. Sites work, youtube videos play...
To achieve that Python 2->3 porting goal I've been using Claude Code AI. Here are my patches, please enjoy!
https://tilde.club/~megastallman/
There is a separate patch for Platform component, and the browser itself. Both are required.
AI has fixed "./mach build", "./mach package" and "./mach clobber" commands for me.

For sure I expect there is some platform-dependent Python code left unported, especially that for necrosoft window. But the overall mission seems achieveable.
I've read a couple of threads here about "evolution, not revolution", and I admit that this code probably will not end up in upstream. Or maybe someone picks it up though.
Anyway, I've resolved my problem and you are welcome to re-use those results.

[Basilisk-Dev]

Pretty cool. Thank you for being honest that it is generated by AI. Some people view that as negative, in my opinion it's fine as long as a human thoroughly reviews the code before merging it in. I actually had the thought the other day to try doing literally this exact same thing. I'll give it a shot next week, taking a break from any development work this weekend.

[jobbautista9]

Windows will probably be a blocker for this since in that OS we use MozillaBuild 3.4 as the unix-like environment for the mach script. It has a Python3 bundled interestingly enough but it's versioned 3.7.9. With Python 3 known for doing changes out-of-the-blue that break backwards compatibility I personally don't want our limited dev time to be spent on making sure our build system is compatible with the latest Python 3 shenanigans (we already have to deal with GCC and Clang). I'd rather the effort be spent in convincing Linux distros and the BSDs to package Tauthon which is an actively-maintained fork of Python 2, and maybe fork MozillaBuild as well to use that (though we don't really need to because I think Tauthon will try to maintain backwards compatibility with Python2).

[athenian200]

Oh wow... there's another Python 3 version of UXP? I really should have checked the forums then... I kinda spent the last month trying to port it over myself after an Epyrus user asked about building with Python 3 and I felt awkward about it.

Did you really do the whole thing with AI, or was it more like AI-assisted coding by hand as you hit issues? I mean, yeah, from what I've seen of AI, it can give simple coding advice and take a good guess of where you should look in a lot of cases, maybe even convert a small script or two, but it can't actually understand all the nuances of the codebase... still, I have heard AI is good at Python, and it seemed like every time I would try to search and expect a Stack Overflow or a Bugzilla post to come up, Copilot would pop up and give me the answer, and then Stack Overflow or Bugzilla would give the same answer 90% of the time (probably because it was trained on them).

If that was really all with AI, then Claude is on another level, my port took me about a month (not counting the time I spent studying Python off and on before even getting started)... and it's not even in a great/perfect state. Though if you say yours works great on Linux, and mine was primarily written on Windows (with an externally-installed Python forced into the MSYS1 environment via PATH changes), then possibly if I look over both we might actually have something usable...

[Moonchild]

Maybe you two should compare notes, diff the code, and see where the differences and potential pain points are?