rnet & ry QA

[jessekrubin]

Hi @0x676e67,

Very cool project. It looks like this is very similar to my (side) project's reqwest bindings (https://github.com/jessekrubin/ry). Curious if you might wanna talk, collaborate, and/or have any critiques of my code!

Very curious what you are planning on doing w/ respect to http3. My reqwest bindings are very much a WIP but are coming along nicely. Curious what is different about rnet/wreq from reqwest and why you decided to fork reqwest

There is a lot of overlap between several of python-structs and what I have in ry. One of the goals of ry is that the sub-crates can be used by other rust-python projects.

Any which way,
Hope all is well,
jesse

[jessekrubin]

I ran your async benchmarks w/ ry and am curious how you got your non-session reqs to be as fast as they are.

[0x676e67]

It seems your benchmark wasn’t run with --release. As for why reqwest is so slow, I think it’s because creating the client is slow. wreq has indeed optimized the client creation speed.

[jessekrubin]

I went back and checked and did run those benchmarks with a release build, the results are similar to that image above.

Very cool that your client creation is so fast.. Let me know if you ever want to team up. I added a default client to ry so one can get around the client creation cost.

[0x676e67]

@jessekrubin bro, you need to fix the issue where the ry.reqwest Python interceptor isn’t initialized. It’s easy to run into errors in rnet benchmarks because of this.

ref: https://github.com/0x676e67/rnet/blob/758d50941b8d976dcb297a0f321867ec9d25e673/src/lib.rs#L173

ry.ryo3.ReqwestError: error sending request for url (http://127.0.0.1:8000/50k) ~ reqwest::Error { kind: Request, url: "http://127.0.0.1:8000/50k", source: hyper_util::client::legacy::Error(Connect, ConnectError("tcp connect error", 127.0.0.1:8000, Os { code: 49, kind: AddrNotAvailable, message: "Can't assign requested address" })) }

thread 'tokio-runtime-worker' (54108248) panicked at /Users/runner/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/pyo3-0.27.2/src/interpreter_lifecycle.rs:117:13:
assertion `left != right` failed: The Python interpreter is not initialized and the `auto-initialize` feature is not enabled.

Consider calling `Python::initialize()` before attempting to use Python APIs.
  left: 0
 right: 0
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

[0x676e67]

Your project is very easy to have this problem, which has never been encountered in other projects. After I deleted your project from the benchmark, everything became normal.

[0x676e67]

https://github.com/PyO3/pyo3/blob/8ffdbd5674798693082a293f9ae415c5ef000acd/src/gil.rs#L55-L58

[jessekrubin]

I'm pretty sure that is not the root problem. AFAICT Initialize is for embedding python IN rust.

POST INVESTIGATING:

The benchmark problem is that for both ry and rnet you don't have try-catches around the get functions (maybe for performance testing?), and on your mac something is funky with the ports being exhausted. What your benchmark did reveal is that neither rnet nor ry handle a python "crash" (throwing an error which is not caught). It is a race condition where a python error is attempting to be created post interpreter crash/shutdown.

I was able to get the EXACT same error/panic from rnet by setting ulimit real low (rhel8).

I have not yet tested on a Mac.

See: jessekrubin/ry#523

[0x676e67]

What platform do you use for testing? What you said makes sense. At least you can know that it will cause class problems in extreme scenarios. In addition, will it cause panic when you throw an Error? I mean Rust's panic.

[0x676e67]

When I comment out Python::initialize(), I can reliably reproduce a panic after an error is thrown. It’s hard to say for sure, but this suggests that Python::initialize() does in fact matter, at least under certain conditions

https://github.com/PyO3/pyo3/blob/0c1d54ef49077b2665cd93cb7445068cd09360f4/src/internal/state.rs#L72

https://github.com/PyO3/pyo3/blob/0c1d54ef49077b2665cd93cb7445068cd09360f4/src/interpreter_lifecycle.rs#L117

[0x676e67]

Your code doesn’t seem to fully fix the issue — there’s still a chance of hitting a panic after an Error is thrown. The root cause is that Python::attach can still be called in some code paths, which then hits the AttachError::NotInitialized branch inside Python::try_attach and crashes in pyo3::interpreter_lifecycle::ensure_initialized(). Across the entire pyo3 codebase, this is the only place that references pyo3::interpreter_lifecycle::ensure_initialized().

When the auto-initialize feature flag is enabled, pyo3 will automatically call Python::initialize() internally to mark the Python interpreter as initialized. This avoids panics caused by race conditions when errors occur. What Python::initialize() does is essentially the same as the logic you described above.

/// Maps a `reqwest::Error` to a `pyo3::PyErr`, handling the case where the
/// Python interpreter is shutting down
///
/// Should prevent panics during interpreter shutdown when background threads
pub(crate) fn map_reqwest_err(e: reqwest::Error) -> pyo3::PyErr {
    #[expect(unsafe_code)]
    if unsafe { pyo3::ffi::Py_IsInitialized() } == 0 {
        loop {
            std::thread::park();
        }
    }
    let maybe_pyerr = Python::try_attach(|_py| {
        let req_err = RyReqwestError::from(e);
        pyo3::PyErr::from(req_err)
    });
    if maybe_pyerr.is_none() {
        tracing::warn!("Interpreter died while processing error. Parking thread.");
        loop {
            std::thread::park();
        }
    }
    maybe_pyerr.expect("no-way-jose")
}

#[cfg(not(any(PyPy, GraalPy)))]
pub(crate) fn initialize() {
    // Protect against race conditions when Python is not yet initialized and multiple threads
    // concurrently call 'initialize()'. Note that we do not protect against
    // concurrent initialization of the Python runtime by other users of the Python C API.
    START.call_once_force(|_| unsafe {
        // Use call_once_force because if initialization panics, it's okay to try again.
        if ffi::Py_IsInitialized() == 0 {
            ffi::Py_InitializeEx(0);

            // Release the GIL.
            ffi::PyEval_SaveThread();
        }
    });
}

[0x676e67]

Looking back, the original point I was trying to make (and I didn’t explain it very well) is that we should avoid panics when an error occurs. Yes, in the benchmarks none of the clients use try/catch-style error handling, because it isn’t necessary — if an error happens, the benchmark should just stop and exit. Failed requests already invalidate the benchmark results anyway.

The real issue is that in a program that is expected to stop normally due to an error, suddenly hitting a Rust panic is very confusing and misleading.

[jessekrubin]

The real issue is that in a program that is expected to stop normally due to an error, suddenly hitting a Rust panic is very confusing and misleading.

I 100% agree, which is why I am pretty invested in figuring out a solution. It is misleading/confusing. That said it does seem to only occur at the periphery on an uncaught exception in scenarios where the python interpreter begins it shut down process.

I will investigate later today when I have time. Plz keep me posted if you figure anything out on your end.

[jessekrubin]

just got to check in on it... I ran the benchmarks on windows 11, rhel8, rocky and ubuntu 22 and could not get the ry panic... I do think this is an weird and interesting problem.

Neither of us set a max pool size, so a huge number of sockets are openning..

I ran the benchmarks several times and got no panic from ry... can you gimme your ulimit -a?

The following is from my macbook (which I dont really ever use to program)::

Food for thought ~ we both get the same connection problem (though that is not a panic)

(.venv) jesse@babydog[[benchmark]]$ python benchmark.py
Starting benchmark with:
  Requests per test: 400
  Thread counts: [1, 4, 8, 16]
  Base URL: http://127.0.0.1:8000

Testing with 20k payload...
Traceback (most recent call last):
  File "/Users/jesse/rnet/python/benchmark/benchmark.py", line 685, in <module>
    main()
    ~~~~^^
  File "/Users/jesse/rnet/python/benchmark/benchmark.py", line 661, in main
    all_results += run_sync_tests(sync_packages, url, requests_number)
                   ~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/jesse/rnet/python/benchmark/benchmark.py", line 474, in run_sync_tests
    SYNC_NON_SESSION_TESTS[session_class](url, requests_number)
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/jesse/rnet/python/benchmark/benchmark.py", line 260, in ry_blocking_non_session_test
    s.get(url).bytes()
    ~~~~~^^^^^
ry.ryo3.ReqwestError: error sending request for url (http://127.0.0.1:8000/20k) ~ reqwest::Error { kind: Request, url: "http://127.0.0.1:8000/20k", source: hyper_util::client::legacy::Error(Connect, ConnectError("tcp connect error", 127.0.0.1:8000, Os { code: 49, kind: AddrNotAvailable, message: "Can't assign requested address" })) }
(.venv) jesse@babydog[[benchmark]]$ python -m ry
{
  "package": "ry",
  "version": "0.0.74",
  "authors": "jesse k. rubin <jessekrubin@gmail.com>",
  "pkgroot": "/Users/jesse/rnet/.venv/lib/python3.13/site-packages/ry",
  "ryo3": {
    "abspath": "/Users/jesse/rnet/.venv/lib/python3.13/site-packages/ry/ryo3.cpython-313-darwin.so",
    "allocator": "mimalloc",
    "build_profile": "release",
    "build_timestamp": "2025-12-16T21:07:04+00:00[UTC]",
    "fsize": 12225280,
    "fsize_str": "12.2 MB",
    "opt-level": 3,
    "target": "aarch64-apple-darwin"
  }
}
(.venv) jesse@babydog[[benchmark]]$ python benchmark.py
Starting benchmark with:
  Requests per test: 400
  Thread counts: [1, 4, 8, 16]
  Base URL: http://127.0.0.1:8000

Testing with 20k payload...
Testing with 50k payload...
Traceback (most recent call last):
  File "/Users/jesse/rnet/python/benchmark/benchmark.py", line 685, in <module>
    main()
    ~~~~^^
  File "/Users/jesse/rnet/python/benchmark/benchmark.py", line 668, in main
    all_results += run_threaded_tests(
                   ~~~~~~~~~~~~~~~~~~^
        sync_packages, url, requests_number, threads
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    )
    ^
  File "/Users/jesse/rnet/python/benchmark/benchmark.py", line 524, in run_threaded_tests
    f.result()
    ~~~~~~~~^^
  File "/Users/jesse/.local/share/uv/python/cpython-3.13.6-macos-aarch64-none/lib/python3.13/concurrent/futures/_base.py", line 449, in result
    return self.__get_result()
           ~~~~~~~~~~~~~~~~~^^
  File "/Users/jesse/.local/share/uv/python/cpython-3.13.6-macos-aarch64-none/lib/python3.13/concurrent/futures/_base.py", line 401, in __get_result
    raise self._exception
  File "/Users/jesse/.local/share/uv/python/cpython-3.13.6-macos-aarch64-none/lib/python3.13/concurrent/futures/thread.py", line 59, in run
    result = self.fn(*self.args, **self.kwargs)
  File "/Users/jesse/rnet/python/benchmark/benchmark.py", line 243, in rnet_blocking_non_session_test
    s.get(url).bytes()
    ~~~~~^^^^^
exceptions.ConnectionError: is_connect error: wreq::Error { kind: Request, uri: http://127.0.0.1:8000/50k, source: Error { kind: Connect, source: Some(ConnectError("tcp connect error", 127.0.0.1:8000, Os { code: 49, kind: AddrNotAvailable, message: "Can't assign requested address" })), connect_info: None } }

my ulimita

(.venv) jesse@babydog[[benchmark]]$ ulimit -a
core file size          (blocks, -c) 0
data seg size           (kbytes, -d) unlimited
file size               (blocks, -f) unlimited
max locked memory       (kbytes, -l) unlimited
max memory size         (kbytes, -m) unlimited
open files                      (-n) 256
pipe size            (512 bytes, -p) 1
stack size              (kbytes, -s) 8176
cpu time               (seconds, -t) unlimited
max user processes              (-u) 2666
virtual memory          (kbytes, -v) unlimited

[0x676e67]

Yes, this is on the latest version. It doesn’t reproduce every time — it happens intermittently. As long as it can exit with an error without triggering a Rust panic, that means the issue is resolved.

~/vscode/rnet main ❯ python3 python/benchmark/benchmark.py -t 1                                                                  rnet 13:19:29
Starting benchmark with:
  Requests per test: 400
  Thread counts: [1]
  Base URL: http://127.0.0.1:8000

Testing with 20k payload...
Testing with 50k payload...
Traceback (most recent call last):
  File "/Users/0x676e67/vscode/rnet/python/benchmark/benchmark.py", line 685, in <module>
    main()
    ~~~~^^
  File "/Users/0x676e67/vscode/rnet/python/benchmark/benchmark.py", line 664, in main
    all_results += run_async_tests(async_packages, url, requests_number)
                   ~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/0x676e67/vscode/rnet/python/benchmark/benchmark.py", line 545, in run_async_tests
    asyncio.run(ASYNC_SESSION_TESTS[session_class](url, requests_number))
    ~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/0x676e67/.local/share/uv/python/cpython-3.13.10-macos-aarch64-none/lib/python3.13/asyncio/runners.py", line 195, in run
    return runner.run(main)
           ~~~~~~~~~~^^^^^^
  File "/Users/0x676e67/.local/share/uv/python/cpython-3.13.10-macos-aarch64-none/lib/python3.13/asyncio/runners.py", line 118, in run
    return self._loop.run_until_complete(task)
           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^
  File "uvloop/loop.pyx", line 1518, in uvloop.loop.Loop.run_until_complete
  File "/Users/0x676e67/vscode/rnet/python/benchmark/benchmark.py", line 340, in ry_async_session_test
    await asyncio.gather(*tasks)
  File "/Users/0x676e67/vscode/rnet/python/benchmark/benchmark.py", line 336, in _fetch
    resp = await s.get(url)
           ^^^^^^^^^^^^^^^^
ry.ryo3.ReqwestError: error sending request for url (http://127.0.0.1:8000/50k) ~ reqwest::Error { kind: Request, url: "http://127.0.0.1:8000/50k", source: hyper_util::client::legacy::Error(Connect, ConnectError("tcp connect error", 127.0.0.1:8000, Os { code: 49, kind: AddrNotAvailable, message: "Can't assign requested address" })) }

thread 'tokio-runtime-worker' (55254045) panicked at /Users/runner/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/pyo3-0.27.2/src/interpreter_lifecycle.rs:117:13:
assertion `left != right` failed: The Python interpreter is not initialized and the `auto-initialize` feature is not enabled.

Consider calling `Python::initialize()` before attempting to use Python APIs.
  left: 0
 right: 0
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
[1]    2200 abort      python3 python/benchmark/benchmark.py -t 1
~/vscode/rnet main ❯ uv pip show ry                                                                                          27s rnet 13:19:59
Name: ry
Version: 0.0.74
Location: /Users/0x676e67/vscode/rnet/.venv/lib/python3.13/site-packages
Requires:
Required-by:
~/vscode/rnet main ❯ ulimit -a                                                                                                   rnet 13:20:04
-t: cpu time (seconds)              unlimited
-f: file size (blocks)              unlimited
-d: data seg size (kbytes)          unlimited
-s: stack size (kbytes)             8176
-c: core file size (blocks)         0
-v: address space (kbytes)          unlimited
-l: locked-in-memory size (kbytes)  unlimited
-u: processes                       10666
-n: file descriptors                1048575
~/vscode/rnet main ❯ python3 python/benchmark/benchmark.py -t 1                                                                  rnet 13:20:13
Starting benchmark with:
  Requests per test: 400
  Thread counts: [1]
  Base URL: http://127.0.0.1:8000

Testing with 20k payload...
Testing with 50k payload...
Traceback (most recent call last):
  File "/Users/0x676e67/vscode/rnet/python/benchmark/benchmark.py", line 685, in <module>
    main()
    ~~~~^^
  File "/Users/0x676e67/vscode/rnet/python/benchmark/benchmark.py", line 664, in main
    all_results += run_async_tests(async_packages, url, requests_number)
                   ~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/0x676e67/vscode/rnet/python/benchmark/benchmark.py", line 545, in run_async_tests
    asyncio.run(ASYNC_SESSION_TESTS[session_class](url, requests_number))
    ~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/0x676e67/.local/share/uv/python/cpython-3.13.10-macos-aarch64-none/lib/python3.13/asyncio/runners.py", line 195, in run
    return runner.run(main)
           ~~~~~~~~~~^^^^^^
  File "/Users/0x676e67/.local/share/uv/python/cpython-3.13.10-macos-aarch64-none/lib/python3.13/asyncio/runners.py", line 118, in run
    return self._loop.run_until_complete(task)
           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^
  File "uvloop/loop.pyx", line 1518, in uvloop.loop.Loop.run_until_complete
  File "/Users/0x676e67/vscode/rnet/python/benchmark/benchmark.py", line 340, in ry_async_session_test
    await asyncio.gather(*tasks)
  File "/Users/0x676e67/vscode/rnet/python/benchmark/benchmark.py", line 336, in _fetch
    resp = await s.get(url)
           ^^^^^^^^^^^^^^^^
ry.ryo3.ReqwestError: error sending request for url (http://127.0.0.1:8000/50k) ~ reqwest::Error { kind: Request, url: "http://127.0.0.1:8000/50k", source: hyper_util::client::legacy::Error(Connect, ConnectError("tcp connect error", 127.0.0.1:8000, Os { code: 49, kind: AddrNotAvailable, message: "Can't assign requested address" })) }

thread 'tokio-runtime-worker' (55259947) panicked at /Users/runner/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/pyo3-0.27.2/src/interpreter_lifecycle.rs:117:13:
assertion `left != right` failed: The Python interpreter is not initialized and the `auto-initialize` feature is not enabled.

Consider calling `Python::initialize()` before attempting to use Python APIs.
  left: 0
 right: 0
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
[1]    2280 abort      python3 python/benchmark/benchmark.py -t 1
~/vscode/rnet main ❯ python3 python/benchmark/benchmark.py -t 1                                                              26s rnet 13:20:54
Starting benchmark with:
  Requests per test: 400
  Thread counts: [1]
  Base URL: http://127.0.0.1:8000

Testing with 20k payload...
Traceback (most recent call last):
  File "/Users/0x676e67/vscode/rnet/python/benchmark/benchmark.py", line 685, in <module>
    main()
    ~~~~^^
  File "/Users/0x676e67/vscode/rnet/python/benchmark/benchmark.py", line 661, in main
    all_results += run_sync_tests(sync_packages, url, requests_number)
                   ~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/0x676e67/vscode/rnet/python/benchmark/benchmark.py", line 474, in run_sync_tests
    SYNC_NON_SESSION_TESTS[session_class](url, requests_number)
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/0x676e67/vscode/rnet/python/benchmark/benchmark.py", line 224, in tls_client_non_session_test
    s.get(url).content
    ~~~~~^^^^^
  File "/Users/0x676e67/vscode/rnet/.venv/lib/python3.13/site-packages/tls_client/sessions.py", line 459, in get
    return self.execute_request(method="GET", url=url, **kwargs)
           ~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/0x676e67/vscode/rnet/.venv/lib/python3.13/site-packages/tls_client/sessions.py", line 442, in execute_request
    raise TLSClientExeption(response_object["body"])
tls_client.exceptions.TLSClientExeption: failed to do request: Get "http://127.0.0.1:8000/20k": dial tcp 127.0.0.1:8000: connect: can't assign requested address
~/vscode/rnet main ❯      

~/vscode/rnet main ❯ python3 python/benchmark/benchmark.py -t 1                                                                  rnet 13:20:58
Starting benchmark with:
  Requests per test: 400
  Thread counts: [1]
  Base URL: http://127.0.0.1:8000

Testing with 20k payload...
Testing with 50k payload...
Traceback (most recent call last):
  File "/Users/0x676e67/vscode/rnet/python/benchmark/benchmark.py", line 685, in <module>
    main()
    ~~~~^^
  File "/Users/0x676e67/vscode/rnet/python/benchmark/benchmark.py", line 664, in main
    all_results += run_async_tests(async_packages, url, requests_number)
                   ~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/0x676e67/vscode/rnet/python/benchmark/benchmark.py", line 545, in run_async_tests
    asyncio.run(ASYNC_SESSION_TESTS[session_class](url, requests_number))
    ~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/0x676e67/.local/share/uv/python/cpython-3.13.10-macos-aarch64-none/lib/python3.13/asyncio/runners.py", line 195, in run
    return runner.run(main)
           ~~~~~~~~~~^^^^^^
  File "/Users/0x676e67/.local/share/uv/python/cpython-3.13.10-macos-aarch64-none/lib/python3.13/asyncio/runners.py", line 118, in run
    return self._loop.run_until_complete(task)
           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^
  File "uvloop/loop.pyx", line 1518, in uvloop.loop.Loop.run_until_complete
  File "/Users/0x676e67/vscode/rnet/python/benchmark/benchmark.py", line 340, in ry_async_session_test
    await asyncio.gather(*tasks)
  File "/Users/0x676e67/vscode/rnet/python/benchmark/benchmark.py", line 336, in _fetch
    resp = await s.get(url)
           ^^^^^^^^^^^^^^^^
ry.ryo3.ReqwestError: error sending request for url (http://127.0.0.1:8000/50k) ~ reqwest::Error { kind: Request, url: "http://127.0.0.1:8000/50k", source: hyper_util::client::legacy::Error(Connect, ConnectError("tcp connect error", 127.0.0.1:8000, Os { code: 49, kind: AddrNotAvailable, message: "Can't assign requested address" })) }

thread 'tokio-runtime-worker' (55273372) panicked at /Users/runner/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/pyo3-0.27.2/src/interpreter_lifecycle.rs:117:13:
assertion `left != right` failed: The Python interpreter is not initialized and the `auto-initialize` feature is not enabled.

Consider calling `Python::initialize()` before attempting to use Python APIs.
  left: 0
 right: 0
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
[1]    2426 abort      python3 python/benchmark/benchmark.py -t 1
~/vscode/rnet main ❯ python3 python/benchmark/benchmark.py -t 1                                                              26s rnet 13:28:51
Starting benchmark with:
  Requests per test: 400
  Thread counts: [1]
  Base URL: http://127.0.0.1:8000

Testing with 20k payload...
Testing with 50k payload...
Traceback (most recent call last):
  File "/Users/0x676e67/vscode/rnet/python/benchmark/benchmark.py", line 685, in <module>
    main()
    ~~~~^^
  File "/Users/0x676e67/vscode/rnet/python/benchmark/benchmark.py", line 664, in main
    all_results += run_async_tests(async_packages, url, requests_number)
                   ~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/0x676e67/vscode/rnet/python/benchmark/benchmark.py", line 545, in run_async_tests
    asyncio.run(ASYNC_SESSION_TESTS[session_class](url, requests_number))
    ~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/0x676e67/.local/share/uv/python/cpython-3.13.10-macos-aarch64-none/lib/python3.13/asyncio/runners.py", line 195, in run
    return runner.run(main)
           ~~~~~~~~~~^^^^^^
  File "/Users/0x676e67/.local/share/uv/python/cpython-3.13.10-macos-aarch64-none/lib/python3.13/asyncio/runners.py", line 118, in run
    return self._loop.run_until_complete(task)
           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^
  File "uvloop/loop.pyx", line 1518, in uvloop.loop.Loop.run_until_complete
  File "/Users/0x676e67/vscode/rnet/python/benchmark/benchmark.py", line 340, in ry_async_session_test
    await asyncio.gather(*tasks)
  File "/Users/0x676e67/vscode/rnet/python/benchmark/benchmark.py", line 336, in _fetch
    resp = await s.get(url)
           ^^^^^^^^^^^^^^^^
ry.ryo3.ReqwestError: error sending request for url (http://127.0.0.1:8000/50k) ~ reqwest::Error { kind: Request, url: "http://127.0.0.1:8000/50k", source: hyper_util::client::legacy::Error(Connect, ConnectError("tcp connect error", 127.0.0.1:8000, Os { code: 49, kind: AddrNotAvailable, message: "Can't assign requested address" })) }

thread 'tokio-runtime-worker' (55279662) panicked at /Users/runner/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/pyo3-0.27.2/src/interpreter_lifecycle.rs:117:13:
assertion `left != right` failed: The Python interpreter is not initialized and the `auto-initialize` feature is not enabled.

Consider calling `Python::initialize()` before attempting to use Python APIs.
  left: 0
 right: 0
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
[1]    2474 abort      python3 python/benchmark/benchmark.py -t 1
~/vscode/rnet main ❯ python3 -m ry                                                                                           26s rnet 13:30:16
{
  "package": "ry",
  "version": "0.0.74",
  "authors": "jesse k. rubin <jessekrubin@gmail.com>",
  "pkgroot": "/Users/0x676e67/vscode/rnet/.venv/lib/python3.13/site-packages/ry",
  "ryo3": {
    "abspath": "/Users/0x676e67/vscode/rnet/.venv/lib/python3.13/site-packages/ry/ryo3.cpython-313-darwin.so",
    "allocator": "mimalloc",
    "build_profile": "release",
    "build_timestamp": "2025-12-16T21:07:04+00:00[UTC]",
    "fsize": 12225280,
    "fsize_str": "12.2 MB",
    "opt-level": 3,
    "target": "aarch64-apple-darwin"
  }
}
~/vscode/rnet main ❯     

[0x676e67]

As for the connection issues, we can just ignore them for now — they’re mainly being used as an error trigger. The goal at this point is to make sure the program exits cleanly on errors instead of hitting a Rust panic.