Uncaught exception during init() when running a script through pycharm

[jleibs]

It appears that certain invocation of pycharm can throw an exception during rr.init() while we are using authkey to generate the recording ID.

I strongly suspect the failure is coming from here:

rerun/rerun_py/src/python_bridge.rs

Lines 1353 to 1368 in 18e2475

	fn authkey(py: Python<'_>) -> Vec<u8> {
	let locals = PyDict::new(py);
	py.run(
	r#"
	import multiprocessing
	# authkey is the same for child and parent processes, so this is how we know we're the same
	authkey = multiprocessing.current_process().authkey
	"#,
	None,
	Some(locals),
	)
	.unwrap();
	let authkey = locals.get_item("authkey").unwrap();
	let authkey: &PyBytes = authkey.downcast().unwrap();
	authkey.as_bytes().to_vec()
	}

Something about the pycharm context causes the import to fail.

At a minimum these unwrap() calls need to be removed and we should warn, then use a random recording-id in the event that authkey fails. This means multiprocessing won't work correctly, but that's still better than crashing.

Know work-arounds

The issue can be avoided by manually setting the recording_id:

import uuid
rr.init("myapp", recording_id=str(uuid.uuid4()))

This supports the theory that the authkey code-path is the culprit since manually setting the recording_id bypasses this code-path.

Additional details

A user reported:

We use rerun-sdk in our own python library for data visualization. When I write and run scripts that use our library (and subsequently tries to launch and log to rerun), I get the following error:
thread '' panicked at 'called Result::unwrap() on an Err value: PyErr { type: <class 'ImportError'>, value: ImportError('import not found')

This only happens when I run the script using the default "Run" method in PyCharm Professional. Looking at it, it seems to run som ipython kernel, and then calls the script using runfile() method, but I can't find docs on it.
If I use the "Debug" method or change the run configuration from the default "Run with Python Console" to "Emulate terminal in output console", it works.

The stack-trace is as follows:

thread '<unnamed>' panicked at 'called `Result::unwrap()` on an `Err` value: PyErr { type: <class 'ImportError'>, value: ImportError('__import__ not found'), traceback: Some(<traceback object at 0x150373a00>) }', rerun_py/src/python_bridge.rs:1180:6
stack backtrace:
   0:        0x1463efb9c - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h105074e3d85f800b
   1:        0x14640f498 - core::fmt::write::h34766cf8fff7af1e
   2:        0x1463eba10 - std::io::Write::write_fmt::hd64c4cf6e7adea59
   3:        0x1463ef9b0 - std::sys_common::backtrace::print::h2a6828a537036cf9
   4:        0x1463f10ec - std::panicking::default_hook::{{closure}}::h4e82ce6ccef941b2
   5:        0x1463f0e44 - std::panicking::default_hook::h29f62f8795c5cb00
   6:        0x1463f15fc - std::panicking::rust_panic_with_hook::h19862cbd0fbda7ba
   7:        0x1463f1530 - std::panicking::begin_panic_handler::{{closure}}::h3f3626935e1669fe
   8:        0x1463effbc - std::sys_common::backtrace::__rust_end_short_backtrace::h5054ef52bd507d0a
   9:        0x1463f128c - _rust_begin_unwind
  10:        0x1464947e0 - core::panicking::panic_fmt::h7e47e10600a90221
  11:        0x146494b18 - core::result::unwrap_failed::h6a1757e313e2d291
  12:        0x1455267c0 - rerun_bindings::python_bridge::new_recording::hed38aea6ac7fe8ae
Process finished with exit code 134 (interrupted by signal 6: SIGABRT)