AssertionError: Unexpected event: <InformationalResponseReceived

[Prinzhorn]

I don't think this was broken recently, originally happened on a pretty outdated branch of mine (as far back as c718d4f) but repros on main as well

Steps to reproduce the behavior:

1. mitmdump
2. curl --insecure --proxy localhost:8080 https://www.shopify.com/

127.0.0.1:40186: client connect
127.0.0.1:40186: server connect www.shopify.com:443 (104.16.255.71:443)
127.0.0.1:40186: mitmproxy has crashed!
Traceback (most recent call last):
  File "/home/alex/src/forks/mitmproxy/mitmproxy/proxy/server.py", line 294, in server_event
    for command in layer_commands:
  File "/home/alex/src/forks/mitmproxy/mitmproxy/proxy/layer.py", line 144, in handle_event
    command = command_generator.send(send)
  File "/home/alex/src/forks/mitmproxy/mitmproxy/proxy/layer.py", line 255, in handle_event
    yield from self._handle(event)
  File "/home/alex/src/forks/mitmproxy/mitmproxy/proxy/layer.py", line 144, in handle_event
    command = command_generator.send(send)
  File "/home/alex/src/forks/mitmproxy/mitmproxy/proxy/layers/http/__init__.py", line 742, in _handle_event
    yield from self.event_to_child(handler, event)
  File "/home/alex/src/forks/mitmproxy/mitmproxy/proxy/layers/http/__init__.py", line 751, in event_to_child
    for command in child.handle_event(event):
  File "/home/alex/src/forks/mitmproxy/mitmproxy/proxy/layer.py", line 144, in handle_event
    command = command_generator.send(send)
  File "/home/alex/src/forks/mitmproxy/mitmproxy/proxy/layers/http/__init__.py", line 619, in passthrough
    for command in self.child_layer.handle_event(event):
  File "/home/alex/src/forks/mitmproxy/mitmproxy/proxy/layer.py", line 144, in handle_event
    command = command_generator.send(send)
  File "/home/alex/src/forks/mitmproxy/mitmproxy/proxy/tunnel.py", line 75, in _handle_event
    yield from self.receive_data(event.data)
  File "/home/alex/src/forks/mitmproxy/mitmproxy/proxy/layers/tls.py", line 291, in receive_data
    yield from self.event_to_child(
  File "/home/alex/src/forks/mitmproxy/mitmproxy/proxy/layers/tls.py", line 357, in event_to_child
    yield from super().event_to_child(event)
  File "/home/alex/src/forks/mitmproxy/mitmproxy/proxy/tunnel.py", line 109, in event_to_child
    for command in self.child_layer.handle_event(event):
  File "/home/alex/src/forks/mitmproxy/mitmproxy/proxy/layer.py", line 144, in handle_event
    command = command_generator.send(send)
  File "/home/alex/src/forks/mitmproxy/mitmproxy/proxy/tunnel.py", line 90, in _handle_event
    yield from self.event_to_child(event)
  File "/home/alex/src/forks/mitmproxy/mitmproxy/proxy/tunnel.py", line 109, in event_to_child
    for command in self.child_layer.handle_event(event):
  File "/home/alex/src/forks/mitmproxy/mitmproxy/proxy/layer.py", line 144, in handle_event
    command = command_generator.send(send)
  File "/home/alex/src/forks/mitmproxy/mitmproxy/proxy/layers/http/__init__.py", line 742, in _handle_event
    yield from self.event_to_child(handler, event)
  File "/home/alex/src/forks/mitmproxy/mitmproxy/proxy/layers/http/__init__.py", line 751, in event_to_child
    for command in child.handle_event(event):
  File "/home/alex/src/forks/mitmproxy/mitmproxy/proxy/layer.py", line 144, in handle_event
    command = command_generator.send(send)
  File "/home/alex/src/forks/mitmproxy/mitmproxy/proxy/layer.py", line 144, in handle_event
    command = command_generator.send(send)
  File "/home/alex/src/forks/mitmproxy/mitmproxy/proxy/layers/http/_http2.py", line 381, in _handle_event
    for cmd in self._handle_event2(event):
  File "/home/alex/src/forks/mitmproxy/mitmproxy/proxy/layers/http/_http2.py", line 425, in _handle_event2
    yield from super()._handle_event(event)
  File "/home/alex/src/forks/mitmproxy/mitmproxy/proxy/layers/http/_http2.py", line 156, in _handle_event
    if (yield from self.handle_h2_event(h2_event)):
  File "/home/alex/src/forks/mitmproxy/mitmproxy/proxy/layers/http/_http2.py", line 461, in handle_h2_event
    return (yield from super().handle_h2_event(event))
  File "/home/alex/src/forks/mitmproxy/mitmproxy/proxy/layers/http/_http2.py", line 234, in handle_h2_event
    raise AssertionError(f"Unexpected event: {event!r}")
AssertionError: Unexpected event: <InformationalResponseReceived stream_id:1, headers:[(b':status', b'103'), (b'link', b'<https://cdn.shopify.com/shopifycloud/brochure/assets/application-e4598a9a40dfeaa77f3cfb05d6d502d3e2f0020008fdfcc09747333d2666c424.css>; as=style; rel=preload, <https://cdn.shopify.com/shopifycloud/brochure/assets/manifests/home/index-c9203e6aecacc53dbe4781dc6fe3805ab20876c009b62307490723e3b96de5ea.css>; as=style; rel=preload')]>

127.0.0.1:40186: GET https://www.shopify.com/ HTTP/2.0
     << HTTP/2.0 200 OK 160k
127.0.0.1:40186: client disconnect
127.0.0.1:40186: server disconnect www.shopify.com:443 (104.16.255.71:443)

System Information

Paste the output of "mitmproxy --version" here.

Mitmproxy: 8.0.0.dev (+202, commit 1e97073)
Python:    3.8.10
OpenSSL:   OpenSSL 1.1.1m  14 Dec 2021
Platform:  Linux-5.11.0-46-generic-x86_64-with-glibc2.29

[Prinzhorn]

Just in case Shopify changes something on their end and it won't be reproducible anymore, here's verbose logs with --set proxy_debug -vvv

shopify.log

[owen800q]

I hit the same issue, any solution?

[rosydawn6]

Hello, getting up to speed as I was also encountering the same issue and found this ticket. When running the above curl with:
Mitmproxy: 8.1.1 binary
Python: 3.10.5
OpenSSL: OpenSSL 3.0.3 3 May 2022
Platform: Linux-5.13.0-52-generic-x86_64-with-glibc2.31

No exception is raised.

When I run the above curl with:
Mitmproxy: 8.0.0 binary
Python: 3.10.2
OpenSSL: OpenSSL 1.1.1n 15 Mar 2022
Platform: Linux-5.13.0-52-generic-x86_64-with-glibc2.31

It raises the InformationalResponseReceived exception