`sendspin server` doesn't work offline

[gdetrez]

When trying to run sendspin serve while not connencted to a network, I get the following exception:

INFO:aiosendspin.server.server:Starting Sendspin server on port 8927
INFO:aiosendspin.server.server:Sendspin server started successfully on 0.0.0.0:8927
ERROR:aiosendspin.server.server:Failed to start server on 0.0.0.0:8927: [Errno 19] No such device
Server error: [Errno 19] No such device
Traceback (most recent call last):
  File "/home/perso/.local/share/uv/tools/sendspin/lib64/python3.14/site-packages/sendspin/cli.py", line 738, in main
    return asyncio.run(_run_serve_mode(args))
           ~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib64/python3.14/asyncio/runners.py", line 204, in run
    return runner.run(main)
           ~~~~~~~~~~^^^^^^
  File "/usr/lib64/python3.14/asyncio/runners.py", line 127, in run
    return self._loop.run_until_complete(task)
           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^
  File "/usr/lib64/python3.14/asyncio/base_events.py", line 719, in run_until_complete
    return future.result()
           ~~~~~~~~~~~~~^^
  File "/home/perso/.local/share/uv/tools/sendspin/lib64/python3.14/site-packages/sendspin/cli.py", line 693, in _run_serve_mode
    return await run_server(serve_config)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/perso/.local/share/uv/tools/sendspin/lib64/python3.14/site-packages/sendspin/serve/__init__.py", line 195, in run_server
    await server.start_server(port=port, discover_clients=False)
  File "/home/perso/.local/share/uv/tools/sendspin/lib64/python3.14/site-packages/aiosendspin/server/server.py", line 692, in start_server
    self._zc = AsyncZeroconf(
               ~~~~~~~~~~~~~^
        ip_version=IPVersion.V4Only,
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        interfaces=[host] if host != "0.0.0.0" else InterfaceChoice.Default,
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    )
    ^
  File "/home/perso/.local/share/uv/tools/sendspin/lib64/python3.14/site-packages/zeroconf/asyncio.py", line 170, in __init__
    self.zeroconf = zc or Zeroconf(
                          ~~~~~~~~^
        interfaces=interfaces,
        ^^^^^^^^^^^^^^^^^^^^^^
    ...<2 lines>...
        apple_p2p=apple_p2p,
        ^^^^^^^^^^^^^^^^^^^^
    )
    ^
  File "/home/perso/.local/share/uv/tools/sendspin/lib64/python3.14/site-packages/zeroconf/_core.py", line 202, in __init__
    listen_socket, respond_sockets = create_sockets(interfaces, unicast, ip_version, apple_p2p=apple_p2p)
                                     ~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/perso/.local/share/uv/tools/sendspin/lib64/python3.14/site-packages/zeroconf/_utils/net.py", line 459, in create_sockets
    add_multicast_member(cast(socket.socket, listen_socket), interface)
    ~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/perso/.local/share/uv/tools/sendspin/lib64/python3.14/site-packages/zeroconf/_utils/net.py", line 350, in add_multicast_member
    listen_socket.setsockopt(socket.IPPROTO_IP, socket.IP_ADD_MEMBERSHIP, _value)
    ~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
OSError: [Errno 19] No such device
ERROR:asyncio:Unclosed client session
client_session: <aiohttp.client.ClientSession object at 0x7fdfab3dde80>

Some more context about my usecase: I'm trying to troubleshoot an esphome sendspin speaker, and I wanted to try a simple setup where the speaker connects directly to my laptop running an access point, and use sendspin-cli to stream a (local) audio file to it.

[balloob]

Sendspin server uses an HTTP server to receive incoming connections from clients, and we use zeroconf to broadcast the existence of that server. If there are no network interfaces to host our server on, crashing seems like a good thing to do?

[gdetrez]

Sorry, I just realized I had a typo in the issue, the command I'm using is sendspin serve not sendspin server.

I'm on linux, so there should generally be at least one interface (loopback), and in my scenario, where I setup a hotspot to connect the speaker, I would have the wifi interface up as well.

To add some context, the exact command I'm trying to run is this:

$ sendspin serve --client http://192.168.1.244:8928/sendspin myfile.mp3

I'm not super familiar with the details of sendspin, but I suspect that zeroconf may not matter here since I'm pointing it to the client URL, is that correct?
Could sendspin-serve just log an error and continue in that case? Or add a --no-zeroconf option?

[balloob]

You're right that in your scenario it does not need Zeroconf. Right now it's not an option that is available in aiosendspin, the underlying library.