Trying real hard to build a fuzzer targeting the CPython JIT, lots of features implemented but not a single crash or bug discovered so far.

Such is life when hunting for crashes in robust code.

This weekend I'll be spinning off a new fuzzer that grew from fusil. Wish me luck

So, my technical report on fuzzing CPython with fusil is almost done.

I'd really appreciate some help categorizing the found issues by relevance/severity/importance or any other name for impact.

Do you have the chops to help with that? And do you have time and interest? Please get in touch if so! And please boost if you can :)

A plot, some tables, links to the report and some discussion are available in this thread:

https://discuss.python.org/t/feedback-on-the-recent-fusil-fuzzing-campaign-of-cpython/91737

Today's activity in the #CPython repository is awesome. Go sprinters!

Let's see if I can get a list of the projects who are planning on sprinting at #PyConUS this week:

* @beeware (Room 317)
* @pyladiescon Web Portal
* Pallets Projects (#Flask, #Jinja, etc.)
* #GNU #Mailman (Room 310)
* Project Mesa
* Read The Docs
* SOSW
* @blackpythondevs Website
* Core #CPython (2 rooms)
* Python Community and Conference Organizers Kit (Room 310)
* Python Packaging
* @aio_libs / @aiohttp
* Free Threaded Python Community Support

(continued in replies)

Writing about #fusil. Some bits:

Fuzzing #CPython with fusil shows it to be a valuable tool for finding and fixing crashers. It started in October 2024 and is ongoing, using free tier cloud instances and personal computers.

Results:
- Fuzzing time: > 25.000 hours
- Fuzzing sessions: > 1.000.000
- Hits: > 50.000
- Issues filled: 52

The original design of fusil makes it well-suited for fuzzing CPython, finding both deep, relevant bugs as well as shallow, low value crashes.

We all know the number of stars on GitHub is an excellent metric for understanding how many people has starred a repo.

CPython now has 66.6k stars

❯ gh repo view python/cpython --json stargazerCount
{
"stargazerCount": 66645
}

Can exactly 21 people, and no more, star it to get to 66666?

https://github.com/python/cpython/

#Python #CPython #GitHub #stargazers #

Do you maintain or contribute to a #Python package that includes a C extension? Would you like to run a fuzzer against it?

If so, let me know and I will run it, or help you to get it running.

The fuzzer is #fusil, which generates random code calling into your functions and methods. It's useful to check for crashes on invalid inputs or unexpected call patterns.

It has found about 50 crashes in #CPython, 20 in #PyPy, 6 in #Numpy etc.

#fuzzing #fuzzer #testing
See here:
https://github.com/devdanzin/fusil/issues/37

Sending a big thank you to Arm for providing ARM GitHub Action runners to CPython ahead of the public preview launch today! https://github.blog/changelog/2025-04-14-windows-arm64-hosted-runners-now-available-in-public-preview/ #python #cpython
https://github.blog/changelog/2025-04-14-windows-arm64-hosted-runners-now-available-in-public-preview/

The Python version diagram has been updated to show the bugfix/security split for each release. (Before, the bars were either completely green or yellow.)

https://devguide.python.org/versions/

It's also zoomed in and shows fewer releases than before. There's another chart further down the page showing all of 2.6 to 3.14. And the wording in the status key has been refreshed to make it clearer.

Thanks to @nedbat and @encukou for updating it!

Following git blame in CPython can quickly take you a long way back!

3 years ago
23 years ago
25 years ago
32 years ago
32 years ago (+ 6 days)

(Checking who first added these tests, it was Guido on 9th March 1994 for Python 2.0.)

https://github.com/python/cpython/blame/83125775e0a5c5088da0cb62b43e7cfd8a04fdc6/Lib/random.py

https://github.com/python/cpython/commit/ff03b1ae5bba4d6712563efb7c77ace57dbe6788

New account, so new #introduction. Let's do it again!

I have a #MastersDegree in #ComputerScience and #ComputerEngineering. I went to #NMU for undergrad and #MSU for my graduate degree. I currently work at #UChicago for the #TMWCenter, which focuses on helping young children acquire language (and therefore other learning skills) faster.

In my spare time, I develop #OpenSourceSoftware such as
- a #SphinxDoc extension that embed #Fediverse comments on your page
- a library to talk to #ManifoldMarkets from native #Python
- a #PredictionMarket manager using the above
- a #transpiler from a subset of Python to #OpenStreetMaps's #OverpassQL
- bug fixes to many other projects, including #mypy, #base58, #attrs, #CPython, & more

I spend a fair bit of my time these days on #MathResearch, specifically into the #ThueMorse Sequence and its extensions.

I'm also a hobbyist editor on OpenStreetMap.

#Demisexual, #transfem, and happily engaged to my #enby sweetheart.

We have two cats: #OpheTheLoaf and #MayalaranTheCat (yes, from #StormlightArchive) See here for more on them!

I speak English fluently, Spanish haltingly, and am trying to learn Chinese

#queer #Chicago