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  1. Miami Dolphins Fans Eager for Truth in Matt LaFleur Rumor Buzz

    The Miami Dolphins are actively searching for their next head coach. They have conducted one virtual interview and…
    #NFL #MiamiDolphins #Miami #Dolphins #buzz #eager #Fans #Football #for #lafleur #Matt #rumor #truth
    rawchili.com/nfl/679554/

  2. Published my first PyPI package today, called lafleur.

    #lafleur is a specialized CPython JIT fuzzer that uses a coverage-guided, evolutionary approach. It executes test cases, observes their effect on the JIT's state by analyzing verbose trace logs, and uses that feedback to guide its mutations, becoming smarter at finding interesting code paths over time.

    Let me know if you use it or have any questions.

    pypi.org/project/lafleur/
    github.com/devdanzin/lafleur

    #Python #CPython #fuzzer #fuzzing #JIT

  3. Published my first PyPI package today, called lafleur.

    #lafleur is a specialized CPython JIT fuzzer that uses a coverage-guided, evolutionary approach. It executes test cases, observes their effect on the JIT's state by analyzing verbose trace logs, and uses that feedback to guide its mutations, becoming smarter at finding interesting code paths over time.

    Let me know if you use it or have any questions.

    pypi.org/project/lafleur/
    github.com/devdanzin/lafleur

    #Python #CPython #fuzzer #fuzzing #JIT

  4. It turns out that, by running it on an interpreter with ASan enabled, I was the culprit of my fuzzer lafleur using way too much memory.

    That even led to me buying some DDR5 to be able to fuzz a bit more comfortably. Running without ASan reduces memory usage to 1/15. So I guess now I'll have some spare RAM, and less money, going forward :)

    I'll enhance the JIT fuzzer to run on a different interpreter than the fuzzing scripts, which benefit from ASan.

    #lafleur #Python #CPython #fuzzer #fuzzing

  5. It turns out that, by running it on an interpreter with ASan enabled, I was the culprit of my fuzzer lafleur using way too much memory.

    That even led to me buying some DDR5 to be able to fuzz a bit more comfortably. Running without ASan reduces memory usage to 1/15. So I guess now I'll have some spare RAM, and less money, going forward :)

    I'll enhance the JIT fuzzer to run on a different interpreter than the fuzzing scripts, which benefit from ASan.

    #lafleur #Python #CPython #fuzzer #fuzzing

  6. lafleur, the CPython JIT fuzzer, now can compare timings for running a piece of code with JIT on and off.

    The idea is that if the run with JIT on is much slower that with JIT off, we have found a performance bug.

    Brandt Bucher suggested this mode. It took a while to get started on it, but it was simple to implement on top of Differential Mode.

    So many modes, so little compute available...

    #lafleur #JIT #fuzzing #fuzzer #CPython #Python

  7. lafleur, the CPython JIT fuzzer, now can compare timings for running a piece of code with JIT on and off.

    The idea is that if the run with JIT on is much slower that with JIT off, we have found a performance bug.

    Brandt Bucher suggested this mode. It took a while to get started on it, but it was simple to implement on top of Differential Mode.

    So many modes, so little compute available...

    #lafleur #JIT #fuzzing #fuzzer #CPython #Python

  8. Differential Mode has just landed in lafleur, the CPython JIT fuzzer. It runs the same code with and without the JIT, compares the result, and flags any discrepancies.

    It does this while mutating the code in a feedback-guided loop, so it evolves the fuzzing scripts trying to find one where the JIT gives wrong results.

    This is actually the 2nd time this feature is implemented (now better and more robust): it used to work, broke, and now is back.

    #lafleur #JIT #fuzzing #fuzzer #CPython #Python

  9. Differential Mode has just landed in lafleur, the CPython JIT fuzzer. It runs the same code with and without the JIT, compares the result, and flags any discrepancies.

    It does this while mutating the code in a feedback-guided loop, so it evolves the fuzzing scripts trying to find one where the JIT gives wrong results.

    This is actually the 2nd time this feature is implemented (now better and more robust): it used to work, broke, and now is back.

    #lafleur #JIT #fuzzing #fuzzer #CPython #Python

  10. Posted a topic about lafleur, the CPython JIT fuzzer I'm developing: discuss.python.org/t/introduci

    It has many details about the project, the results (4 JIT crashes so far), calls for help and ideas for the future.

    If any of this interests you, please give a read. Boosts welcome :)

    #lafleur #fusil #Python #fuzzer #fuzzing #CPython #JIT

  11. Preparing a post about lafleur, the CPython JIT fuzzer I develop.

    It has found 4 JIT crashes so far:
    #136996: "JIT: `executor->vm_data.valid` assertion failure in `unlink_executor`".
    #137007: "JIT: assertion failure in _PyObject_GC_UNTRACK".
    #137728: "Assertion failure or `SystemError` in `_PyEval_EvalFrameDefault` in a JIT build".
    #137762: "Assertion failure in `optimize_uops` in a JIT build".

    Contributions welcome!

    github.com/search?q=repo%3Apyt

    #Python #CPython #fuzzer #fuzzing #lafleur #JIT

  12. Here's how lafleur works:

    Starts from a corpus of seed files (generated by fusi)l. It runs each file and parses the JIT debug output to record micro ops (UOPs) and edges between them.

    Then it applies mutations to these files and when a mutation results in a new UOP or edge, it adds the mutated file to the corpus.

    All the while, it monitors the execution of these files for crashes.

    And it's smart about which file to mutate next.

    Simple, eh?

    #Python #CPython #fuzzer #fuzzing #fusil #lafleur

  13. One obvious thing from fuzzing the CPython JIT with the lafleur fuzzer is that finding crashes is much lower probability than fuzzing CPython with fusil.

    Whenever fusil found a crash, it would find hits for it again and again pretty quickly.

    With lafleur, we only got 3 hits (2 issues) in thousands of fuzzing hours.

    I'm throwing more compute at it, but maybe we'll need to improve the core ideas to get better results.

    github.com/devdanzin/lafleur

    #Python #CPython #fuzzer #fuzzing #fusil #lafleur

  14. Reviewed the 3 PRs we got for lafleur: github.com/devdanzin/lafleur/p

    All 3 marked as "good first issue". They've clear signs of being created by or with help from AI, like tentative code ("# do this in case... ") and removing docstrings.

    Merged one and gave feedback on 2, including tips on how to get AI to fix their issues.

    I might get unfollows for this, but I welcome AI generated code as long as it's good enough. In fact, AI made this project viable.

    #Python #fuzzer #fuzzing #fusil #lafleur #AI

  15. Busy day, good day: the new CPython fuzzer lafleur found its first 2 crashes this morning!

    Happiness only marred by the bad job I did reducing the testcases and making the reports reproducible. Thanks Brandt Bucher and and Ken Jin for the patience! Next bug reports will be more polished and reliable.

    Also, we got 3 new PRs for the fuzzer but I didn't have time to review them, will have to leave that for tomorrow.

    github.com/devdanzin/lafleur/

    #Python #CPython #fuzzer #fuzzing #fusil #lafleur

  16. Launching a new project on a Sunday night: lafleur, a CPython JIT fuzzer.

    github.com/devdanzin/lafleur

    It's a feedback driven fuzzer (using JIT debug output) with corpus prioritization and JIT-targeted AST-based mutations. Calling it "evolutionary" may be a stretch, but sounds good.

    It's also a fuzzer that so far hasn't found any crashes or bugs. Still working on that ;)

    If you want to understand how it works, there is a good amount of docs.

    #Python #CPython #lafleur #fusil #Fuzzer #Fuzzing #JIT

  17. 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 🙂

    #Python #CPython #JIT #Fuzzer #Fuzzing #fusil #lafleur

  18. [blogue / rappel]

    «Le feu dans les yeux du Rocket

    Les feintes savantes du Gros Bill

    Toute la fougue du Pocket Rocket

    Jacques Plante et son p’tit nez fragile

    La grâce artistique de Ti-Guy»

    oreilletendue.com/2025/05/20/c

    #hockey #ch #habs #chansonqc #richard #béliveau #plante #lafleur #rocket #oreilletendue #SportPhotography

  19. Played La Fleur and had a ton of fun with it.

    Played Madame Marguerite and used my garden's labyrinthine paths to seduce Louise Lorraine to be my romantic companion.

    Any boardgame where girls kiss has my unequivocal stamp of approval.

    #BoardGame #BoardGames #LaFleur #TheyWereRoomates #WhoWereLesbians #AndFuckedRegularly

  20. [blogue / rappel]
    «Mes bras meurtris vous tendent le flambeau
    J’suis peut-être pas Guy Lafleur mais j’n’ai faite des tours du chapeau
    Ma p’tite carrière passe sous l’silence
    Ça y est, je tire ma révérence»
    oreilletendue.com/2025/05/16/c
    #hockey #ch #habs #lafleur #richard #rocket #bouchard #messier #sport #oreilletendue

  21. [blogue / rappel]
    «Chez les Anglais
    On t’appelait Flower
    T’as mis du rêve
    Et du rose dans nos vies
    Car simplement
    Tu étais Guy Lafleur»
    oreilletendue.com/2025/05/15/c
    #hockey #ch #habs #lafleur #chansonqc #sport #oreilletendue

  22. [blogue / rappel]
    «J’vous l’dis
    Moé j’m’ennuie de Ti-Guy Lafleur
    Lui quand y jouait
    Y en avait du cœur
    Y nous en a faitte voir
    D’toutes les couleurs
    J’vous dis
    Moé j’m’ennuie de Ti-Guy Lafleur»
    oreilletendue.com/2025/05/14/c
    #lafleur #hockey #ch #habs #sport #oreilletendue #chansonqc

  23. [blogue / rappel]
    «Y s’pense encore bon pour quelques saisons
    Quand tout à coup un soir sur la patinoire
    Un autre démon blond fait son apparition
    Et prend possession de la p’tite rondelle noire»
    oreilletendue.com/2025/05/13/c
    #lafleur #hockey #chansonqc #sport #oreilletendue

  24. [blogue / rappel]
    «C’est Ti-Guy Lafleur qui est si populaire
    [OT] C’est Ti-Guy Lafleur qui score tout l’temps
    [Chœur d’enfants] C’est Ti-Guy Lafleur qui est si populaire
    [Chœur d’enfants] C’est Ti-Guy Lafleur qui score tout l’temps»
    oreilletendue.com/2025/05/12/c
    #chansonqc #lafleur #hockey #sport #habs #ch #oreilletendue