ERROR: unable to receive /return message from sclang

[avallintine]

Windows 10 Pro, Python 3.11.9, SuperCollider 3.13.0.

Also tested with Python 3.12 and SuperCollider 3.12.2 and 3.11.2 with same outcome.

Haven't had any problems using SuperCollider through the IDE.

Tried increasing timeout on line 459 to 20 seconds and disabling Windows Firewall, but no luck.

Please help :)

Output of IPython session:

Python 3.11.9 | packaged by Anaconda, Inc. | (main, Apr 19 2024, 16:40:41) [MSC v.1916 64 bit (AMD64)]
Type 'copyright', 'credits' or 'license' for more information
IPython 8.25.0 -- An enhanced Interactive Python. Type '?' for help.

In [1]: import sc3nb as scn

In [2]: sc = scn.startup()
<IPython.core.display.Javascript object>
[sclang | start reading ]
Starting sclang process... Done.
Registering OSC /return callback in sclang... Done.
Loading default sc3nb SynthDefs... Done.
[scsynth | start reading ]
Booting SuperCollider Server... Done.
ERROR: unable to receive /return message from sclang
sclang output: (also see console)

sc3> r['callback'].value("NetAddr.langPort", "127.0.0.1", 57131);
-> 57120
sc3>
sc3>
sc3> Requested notification messages from server 'sc3nb_remote'
sc3nb_remote: server process has maxLogins 8 - adjusting my options accordingly.
sc3nb_remote: keeping clientID (0) as confirmed by server process.
---------------------------------------------------------------------------
ProcessTimeout                            Traceback (most recent call last)
File ~\Anaconda3\envs\sc3nb_foo\Lib\site-packages\sc3nb\sclang.py:459, in SCLang.connect_to_server(self, server)
    458 try:  # if there are 'too many users' we failed. So the Exception is the successful case!
--> 459     self.read(expect="too many users", timeout=0.3, print_error=False)
    460 except ProcessTimeout:

File ~\Anaconda3\envs\sc3nb_foo\Lib\site-packages\sc3nb\sclang.py:384, in SCLang.read(self, expect, timeout, print_error)
    383     print(error_str + timeout_error.output)
--> 384 raise timeout_error

File ~\Anaconda3\envs\sc3nb_foo\Lib\site-packages\sc3nb\sclang.py:371, in SCLang.read(self, expect, timeout, print_error)
    370 try:
--> 371     return self.process.read(expect=expect, timeout=timeout)
    372 except ProcessTimeout as timeout_error:

File ~\Anaconda3\envs\sc3nb_foo\Lib\site-packages\sc3nb\process_handling.py:247, in Process.read(self, expect, timeout)
    246 if time.time() >= timeout_time:
--> 247     raise ProcessTimeout(
    248         executable=self.executable,
    249         timeout=timeout,
    250         output=out,
    251         expected=expect,
    252     )
    253 try:

ProcessTimeout: Reading of sclang timed out after 0.3s while expecting: "too many users"

During handling of the above exception, another exception occurred:

Empty                                     Traceback (most recent call last)
File ~\Anaconda3\envs\sc3nb_foo\Lib\site-packages\sc3nb\sclang.py:309, in SCLang.cmd(self, code, pyvars, verbose, discard_output, get_result, print_error, get_output, timeout)
    308 try:
--> 309     return_val = self._server.returns.get(timeout)
    310 except Empty as empty_exception:

File ~\Anaconda3\envs\sc3nb_foo\Lib\site-packages\sc3nb\osc\osc_communication.py:639, in MessageQueue.get(self, timeout, skip)
    638     self._skips -= 1
--> 639 val = self._queue.get(block=True, timeout=timeout)
    640 self._queue.task_done()

File ~\Anaconda3\envs\sc3nb_foo\Lib\queue.py:179, in Queue.get(self, block, timeout)
    178 if remaining <= 0.0:
--> 179     raise Empty
    180 self.not_empty.wait(remaining)

Empty:

The above exception was the direct cause of the following exception:

SCLangError                               Traceback (most recent call last)
File ~\Anaconda3\envs\sc3nb_foo\Lib\site-packages\sc3nb\sc.py:280, in SC._try_to_connect(self)
    279 try:
--> 280     self._sclang.connect_to_server(self._server)
    281 except Exception as excep:

File ~\Anaconda3\envs\sc3nb_foo\Lib\site-packages\sc3nb\sclang.py:462, in SCLang.connect_to_server(self, server)
    461 self._server = server
--> 462 self._port = self.cmdg("NetAddr.langPort", verbose=False)
    463 _LOGGER.info("Connecting %s with %s", self._server, self)

File ~\Anaconda3\envs\sc3nb_foo\Lib\site-packages\sc3nb\sclang.py:344, in SCLang.cmdg(self, code, **kwargs)
    343     kwargs["pyvars"] = parse_pyvars(code)
--> 344 return self.cmd(code, get_result=True, **kwargs)

File ~\Anaconda3\envs\sc3nb_foo\Lib\site-packages\sc3nb\sclang.py:316, in SCLang.cmd(self, code, pyvars, verbose, discard_output, get_result, print_error, get_output, timeout)
    315             print(out)
--> 316         raise SCLangError(
    317             "unable to receive /return message from sclang", sclang_output=out
    318         ) from empty_exception
    319 out = self.read(expect=self._repl_return, timeout=timeout)

SCLangError: unable to receive /return message from sclang

The above exception was the direct cause of the following exception:

RuntimeError                              Traceback (most recent call last)
Cell In[2], line 1
----> 1 sc = scn.startup()

File ~\Anaconda3\envs\sc3nb_foo\Lib\site-packages\sc3nb\sc.py:67, in startup(start_server, scsynth_path, start_sclang, sclang_path, magic, scsynth_options, with_blip, console_logging, allowed_parents, timeout)
     64         magics.load_ipython_extension(ipy)
     66 if SC.default is None:
---> 67     SC.default = SC(
     68         start_server=start_server,
     69         scsynth_path=scsynth_path,
     70         start_sclang=start_sclang,
     71         sclang_path=sclang_path,
     72         scsynth_options=scsynth_options,
     73         with_blip=with_blip,
     74         console_logging=console_logging,
     75         allowed_parents=allowed_parents,
     76         timeout=timeout,
     77     )
     78 else:
     79     _LOGGER.warning("SC already started")

File ~\Anaconda3\envs\sc3nb_foo\Lib\site-packages\sc3nb\sc.py:177, in SC.__init__(self, start_server, scsynth_path, start_sclang, sclang_path, scsynth_options, with_blip, console_logging, allowed_parents, timeout)
    170         self.start_sclang(
    171             sclang_path=sclang_path,
    172             console_logging=self._console_logging,
    173             allowed_parents=allowed_parents,
    174             timeout=timeout,
    175         )
    176     if start_server:
--> 177         self.start_server(
    178             scsynth_path=scsynth_path,
    179             scsynth_options=scsynth_options,
    180             console_logging=self._console_logging,
    181             with_blip=with_blip,
    182             allowed_parents=allowed_parents,
    183             timeout=timeout,
    184         )
    185 except Exception:
    186     if SC.default is self:

File ~\Anaconda3\envs\sc3nb_foo\Lib\site-packages\sc3nb\sc.py:271, in SC.start_server(self, scsynth_options, scsynth_path, console_logging, with_blip, allowed_parents, timeout)
    269         raise RuntimeError(f"Starting scsynth failed - {excep}") from excep
    270     else:
--> 271         self._try_to_connect()
    272 else:
    273     _LOGGER.warning("scsynth already started")

File ~\Anaconda3\envs\sc3nb_foo\Lib\site-packages\sc3nb\sc.py:282, in SC._try_to_connect(self)
    280     self._sclang.connect_to_server(self._server)
    281 except Exception as excep:
--> 282     raise RuntimeError(
    283         f"connecting {self._sclang} to {self._server} failed"
    284     ) from excep

RuntimeError: connecting <SCLang process=<Process 'sclang' (running) pid=1788>> to <SCServer addr=('127.0.0.1', 57110), process=<Process 'scsynth' (running) pid=14840>> failed

[avallintine]

Tried increasing timeout on line 459 to 20 seconds and disabling Windows Firewall, but no luck.

Also tried increasing global timeout:

scn.startup(timeout=20)

But it still times out when waiting for a response from sclang.

Not sure if this helps identify the problem, but while running the same code in VS Code I am getting a different error:

Starting sclang process... [sclang | start reading ]
Done.
Registering OSC /return callback in sclang... Timeout while reading sclang
expected: "->" (sclang return value)
output until timeout below: (also see console)
----------------------------------------------
sc3> "sc3nb - Registering OSC /return callback".postln; r = r ? (); r.callback =  { arg code, ip, port; var result = code.interpret; var addr = NetAddr.new(ip, port); var prependSize = { arg elem; if (elem.class == Array){ elem = [elem.size] ++ elem.collect(prependSize); }{ elem; }; }; var msgContent = prependSize.value(result); addr.sendMsg("ReplyAddress.RETURN_ADDR", msgContent); result; };
sc3nb - Registering OSC /return callback
-> ( 'callback': a Function )
sc3>

Traceback (most recent call last):
  File "c:\Users\avallintine\Anaconda3\envs\supercollider_foo\Lib\site-packages\sc3nb\sc.py", line 214, in start_sclang
    self._sclang.start(
  File "c:\Users\avallintine\Anaconda3\envs\supercollider_foo\Lib\site-packages\sc3nb\sclang.py", line 121, in start
    self.init()
  File "c:\Users\avallintine\Anaconda3\envs\supercollider_foo\Lib\site-packages\sc3nb\sclang.py", line 131, in init
    self.cmds(
  File "c:\Users\avallintine\Anaconda3\envs\supercollider_foo\Lib\site-packages\sc3nb\sclang.py", line 338, in cmds
    return self.cmd(code, verbose=False, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "c:\Users\avallintine\Anaconda3\envs\supercollider_foo\Lib\site-packages\sc3nb\sclang.py", line 319, in cmd
    out = self.read(expect=self._repl_return, timeout=timeout)
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "c:\Users\avallintine\Anaconda3\envs\supercollider_foo\Lib\site-packages\sc3nb\sclang.py", line 384, in read
    raise timeout_error
  File "c:\Users\avallintine\Anaconda3\envs\supercollider_foo\Lib\site-packages\sc3nb\sclang.py", line 371, in read
    return self.process.read(expect=expect, timeout=timeout)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "c:\Users\avallintine\Anaconda3\envs\supercollider_foo\Lib\site-packages\sc3nb\process_handling.py", line 247, in read
    raise ProcessTimeout(
sc3nb.process_handling.ProcessTimeout: Reading of sclang timed out after 1s while expecting: "->"

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "D:\projects\supercollider_foo\sc3nb_foo.py", line 3, in <module>
    sc = scn.startup(timeout=20)
         ^^^^^^^^^^^^^^^^^^^^^^^
  File "c:\Users\avallintine\Anaconda3\envs\supercollider_foo\Lib\site-packages\sc3nb\sc.py", line 67, in startup
    SC.default = SC(
                 ^^^
  File "c:\Users\avallintine\Anaconda3\envs\supercollider_foo\Lib\site-packages\sc3nb\sc.py", line 170, in __init__
    self.start_sclang(
  File "c:\Users\avallintine\Anaconda3\envs\supercollider_foo\Lib\site-packages\sc3nb\sc.py", line 222, in start_sclang
    raise RuntimeError(f"Starting sclang failed - {excep}") from excep
RuntimeError: Starting sclang failed - Reading of sclang timed out after 1s while expecting: "->"
[sclang | reached EOF ]
Exiting sclang... Done.

[dreinsch]

Sorry for the late reply. I hope this still helps!
This seems to be the following issue - #18
Please install and try using the development version by using
pip install git+https://github.com/interactive-sonification/sc3nb.git@develop

[avallintine]

That worked. Thanks!

[LFSaw]

this also fixes it on OSX, apparently. Thanks!

[courageousdissonance]

Hi! I had the same issue and this fixed it, but now I have another one.

(I use Jupyter Notebook on Mac OS 14.5, Python 3.12, SuperCollider 3.12.2)

for anything that needs OSC Communication I get the following output:

(here after input: sc.server.reply_addresses)

`---------------------------------------------------------------------------
Empty Traceback (most recent call last)
File /opt/anaconda3/lib/python3.12/site-packages/sc3nb/osc/osc_communication.py:1063, in OSCCommunication._handle_outgoing_message(self, message, receiver_address, await_reply, timeout)
1062 if await_reply:
-> 1063 return self._msg_queues[reply_addr].get(timeout, skip=True)
1064 else:

File /opt/anaconda3/lib/python3.12/site-packages/sc3nb/osc/osc_communication.py:639, in MessageQueue.get(self, timeout, skip)
638 self._skips -= 1
--> 639 val = self._queue.get(block=True, timeout=timeout)
640 self._queue.task_done()

File /opt/anaconda3/lib/python3.12/queue.py:179, in Queue.get(self, block, timeout)
178 if remaining <= 0.0:
--> 179 raise Empty
180 self.not_empty.wait(remaining)

Empty:

The above exception was the direct cause of the following exception:

OSCCommunicationError Traceback (most recent call last)
Cell In[249], line 1
----> 1 sc.server.msg("/status")

File /opt/anaconda3/lib/python3.12/site-packages/sc3nb/osc/osc_communication.py:1128, in OSCCommunication.msg(self, msg_addr, msg_params, bundle, receiver, await_reply, timeout)
1095 def msg(
1096 self,
1097 msg_addr: str,
(...)
1103 timeout: float = 5,
1104 ) -> Optional[Any]:
1105 """Creates and sends OSC message over UDP.
1106
1107 Parameters
(...)
1126 reply if await_reply and there is a reply for this
1127 """
-> 1128 return self.send(
1129 OSCMessage(msg_addr, msg_params),
1130 bundle=bundle,
1131 receiver=receiver,
1132 await_reply=await_reply,
1133 timeout=timeout,
1134 )

File /opt/anaconda3/lib/python3.12/site-packages/sc3nb/osc/osc_communication.py:1020, in OSCCommunication.send(self, package, receiver, bundle, await_reply, timeout)
1017 raise RuntimeError("Could not send data. Socket connection broken.")
1019 if isinstance(package, OSCMessage):
-> 1020 return self._handle_outgoing_message(
1021 package, receiver_address, await_reply, timeout
1022 )
1023 elif isinstance(package, Bundler):
1024 # logging
1025 if _LOGGER.isEnabledFor(logging.INFO):

File /opt/anaconda3/lib/python3.12/site-packages/sc3nb/osc/osc_communication.py:1078, in OSCCommunication._handle_outgoing_message(self, message, receiver_address, await_reply, timeout)
1076 error_msg = f"Error when sending '{message.address}' message to "
1077 error_msg += f"{self._check_sender(receiver_address)}"
-> 1078 raise OSCCommunicationError(error_msg, message) from error

OSCCommunicationError: Failed to get reply at 'MasterControlReply.STATUS_REPLY' after '/status' message to scsynth`

[courageousdissonance]

Update:

Was able to fix the problem by implementing what you wrote here:

#18 (comment)

[dreinsch]

Hi. Glad you found the solution and thanks for the update!