# Error while creating actor class **URL:** \ **Category:** Ray Core\ **Created:** [August 25, 2022, 10:04am UTC](https://discuss.ray.io/t/error-while-creating-actor-class/7323 "2022-08-25T10:04:27Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![shyampatel](https://avatars.discourse-cdn.com/v4/letter/s/cab0a1/32.png) [@shyampatel](https://discuss.ray.io/u/shyampatel)\ **Post date:** [August 25, 2022, 10:04am UTC](https://discuss.ray.io/t/error-while-creating-actor-class/7323/1 "2022-08-25T10:04:27Z")
- High: It blocks me to complete my task. Getting error while creating instance of actor class. Error: ```auto ValueError: callable gi.FunctionInfo(signal_handler_disconnect) is not supported by signature ``` You can reproduce error with following block of code: ```auto import gi import ray gi.require_version('Gst', '1.0') gi.require_version('GstRtspServer', '1.0') from gi.repository import Gst, GstRtspServer, GLib @ray.remote class GstServer(GstRtspServer.RTSPServer): def __init__ (self, **properties): Gst.init(None) super(GstServer, self). __init__ (**properties) self.loop = GLib.MainLoop() def start_streaming(self): self.loop.run() def stop_streaming(self): self.loop.quit() if __name__ == " __main__": obj = GstServer.remote() obj.start_streaming() ``` Notes: - It’s running without ray actor conversion. ---
**Author:** ![jjyao](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.ray.io/jjyao/32/1799_2.png) [@jjyao](https://discuss.ray.io/u/jjyao)\ **Post date:** [August 25, 2022, 5:57pm UTC](https://discuss.ray.io/t/error-while-creating-actor-class/7323/2 "2022-08-25T17:57:20Z")
How can I install `gi`? ---
**Author:** ![shyampatel](https://avatars.discourse-cdn.com/v4/letter/s/cab0a1/32.png) [@shyampatel](https://discuss.ray.io/u/shyampatel)\ **Post date:** [August 26, 2022, 4:29am UTC](https://discuss.ray.io/t/error-while-creating-actor-class/7323/3 "2022-08-26T04:29:19Z")
You can follow this: > ---
**Author:** ![jjyao](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.ray.io/jjyao/32/1799_2.png) [@jjyao](https://discuss.ray.io/u/jjyao)\ **Post date:** [August 26, 2022, 9:53pm UTC](https://discuss.ray.io/t/error-while-creating-actor-class/7323/4 "2022-08-26T21:53:52Z")
I successfully installed `gi` but I was not able to run your script ```auto Traceback (most recent call last): File "test.py", line 4, in gi.require_version('Gst', '1.0') File "/home/ubuntu/anaconda3/envs/debug/lib/python3.6/site-packages/gi/ __init__.py", line 126, in require_version raise ValueError('Namespace %s not available' % namespace) ValueError: Namespace Gst not available ``` Also I found a bug in your code: instead of `obj.start_streaming()`, it should be `obj.start_streaming.remote()`. ---
**Author:** ![shyampatel](https://avatars.discourse-cdn.com/v4/letter/s/cab0a1/32.png) [@shyampatel](https://discuss.ray.io/u/shyampatel)\ **Post date:** [August 27, 2022, 7:04am UTC](https://discuss.ray.io/t/error-while-creating-actor-class/7323/5 "2022-08-27T07:04:39Z")
> [@jjyao](#): > > `ValueError: Namespace Gst not available` You have to install GStreamer. You can use following command to install it: `sudo apt-get install gstreamer-1.0` ---
**Author:** ![jjyao](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.ray.io/jjyao/32/1799_2.png) [@jjyao](https://discuss.ray.io/u/jjyao)\ **Post date:** [August 30, 2022, 3:27am UTC](https://discuss.ray.io/t/error-while-creating-actor-class/7323/6 "2022-08-30T03:27:00Z")
Install `gstreamer-1.0` doesn’t fix the issue for me. ---
**Author:** ![shyampatel](https://avatars.discourse-cdn.com/v4/letter/s/cab0a1/32.png) [@shyampatel](https://discuss.ray.io/u/shyampatel)\ **Post date:** [August 30, 2022, 6:12am UTC](https://discuss.ray.io/t/error-while-creating-actor-class/7323/7 "2022-08-30T06:12:56Z")
Run the following command: ```auto sudo apt-get install python-gi python3-gi \ gstreamer1.0-tools \ gir1.2-gstreamer-1.0 \ gir1.2-gst-rtsp-server-1.0 \ gir1.2-gst-plugins-base-1.0 \ gstreamer1.0-plugins-good \ gstreamer1.0-plugins-ugly \ gstreamer1.0-plugins-bad \ gstreamer1.0-libav ``` If you face any issue in import `Gst` after running above command, please share the issue/error with me. ---
**Author:** ![jjyao](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.ray.io/jjyao/32/1799_2.png) [@jjyao](https://discuss.ray.io/u/jjyao)\ **Post date:** [August 31, 2022, 5:15pm UTC](https://discuss.ray.io/t/error-while-creating-actor-class/7323/8 "2022-08-31T17:15:54Z")
Still doesn’t work for me. ```auto Traceback (most recent call last): File "test.py", line 4, in gi.require_version('Gst', '1.0') AttributeError: module 'gi' has no attribute 'require_version' ``` ---
**Author:** ![shyampatel](https://avatars.discourse-cdn.com/v4/letter/s/cab0a1/32.png) [@shyampatel](https://discuss.ray.io/u/shyampatel)\ **Post date:** [August 31, 2022, 5:31pm UTC](https://discuss.ray.io/t/error-while-creating-actor-class/7323/9 "2022-08-31T17:31:04Z")
> [@jjyao](#): > > `AttributeError: module 'gi' has no attribute 'require_version'` Can you try install following modules: `pip install gobject PyGObject` ---
**Author:** ![shyampatel](https://avatars.discourse-cdn.com/v4/letter/s/cab0a1/32.png) [@shyampatel](https://discuss.ray.io/u/shyampatel)\ **Post date:** [September 3, 2022, 11:55am UTC](https://discuss.ray.io/t/error-while-creating-actor-class/7323/10 "2022-09-03T11:55:33Z")
Hi @jjyao , Can you please confirm whether you can reproduce the error or not? ---
**Author:** ![jjyao](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.ray.io/jjyao/32/1799_2.png) [@jjyao](https://discuss.ray.io/u/jjyao)\ **Post date:** [September 5, 2022, 5:58am UTC](https://discuss.ray.io/t/error-while-creating-actor-class/7323/11 "2022-09-05T05:58:29Z")
Sorry @shyampatel for the late reply. I was not able to run `pip install gobject PyGObject`, it failed with ```auto 'pkg-config' not found. Command ['pkg-config', '--print-errors', '--exists', 'cairo >= 1.15.10'] ---------------------------------------- ERROR: Failed building wheel for pycairo Failed to build PyGObject pycairo ERROR: Could not build wheels for pycairo, which is required to install pyproject.toml-based projects ``` But I was able to install it via conda `conda install -c conda-forge pygobject`. After that, I’m still facing ```auto Traceback (most recent call last): File "test.py", line 4, in gi.require_version('Gst', '1.0') File "/home/ubuntu/anaconda3/envs/debug/lib/python3.6/site-packages/gi/ __init__.py", line 126, in require_version raise ValueError('Namespace %s not available' % namespace) ValueError: Namespace Gst not available ``` even after I apt-get install everything. ---
**Author:** ![jjyao](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.ray.io/jjyao/32/1799_2.png) [@jjyao](https://discuss.ray.io/u/jjyao)\ **Post date:** [September 5, 2022, 6:02am UTC](https://discuss.ray.io/t/error-while-creating-actor-class/7323/12 "2022-09-05T06:02:22Z")
Probably it’s easier for you to help me debug it: Could you share the entire stacktrace of the error you received? Where did the error happen? ---
**Author:** ![krishna](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.ray.io/krishna/32/3146_2.png) [@krishna](https://discuss.ray.io/u/krishna)\ **Post date:** [September 5, 2022, 10:00am UTC](https://discuss.ray.io/t/error-while-creating-actor-class/7323/13 "2022-09-05T10:00:41Z")
Hi JJyao, Please find the complete stacktrace below: ```auto Traceback (most recent call last): File "/home/kandhavarapu/projects/concor/warehouse/test.py", line 9, in class GstServer(GstRtspServer.RTSPServer): File "/home/kandhavarapu/.local/lib/python3.10/site-packages/ray/_private/worker.py", line 2896, in remote return _make_remote(args[0], {}) File "/home/kandhavarapu/.local/lib/python3.10/site-packages/ray/_private/worker.py", line 2597, in _make_remote return ray.actor._make_actor(function_or_class, options) File "/home/kandhavarapu/.local/lib/python3.10/site-packages/ray/actor.py", line 1342, in _make_actor _inject_tracing_into_class(Class) File "/home/kandhavarapu/.local/lib/python3.10/site-packages/ray/util/tracing/tracing_helper.py", line 540, in _inject_tracing_into_class _add_param_to_signature( File "/home/kandhavarapu/.local/lib/python3.10/site-packages/ray/util/tracing/tracing_helper.py", line 106, in _add_param_to_signature old_sig = inspect.signature(function) File "/usr/lib/python3.10/inspect.py", line 3247, in signature return Signature.from_callable(obj, follow_wrapped=follow_wrapped, File "/usr/lib/python3.10/inspect.py", line 2995, in from_callable return _signature_from_callable(obj, sigcls=cls, File "/usr/lib/python3.10/inspect.py", line 2558, in _signature_from_callable raise ValueError('callable {!r} is not supported by signature'.format(obj)) ValueError: callable gi.FunctionInfo(signal_handler_disconnect) is not supported by signature ``` ---
**Author:** ![shyampatel](https://avatars.discourse-cdn.com/v4/letter/s/cab0a1/32.png) [@shyampatel](https://discuss.ray.io/u/shyampatel)\ **Post date:** [September 5, 2022, 11:19am UTC](https://discuss.ray.io/t/error-while-creating-actor-class/7323/14 "2022-09-05T11:19:28Z")
> [@jjyao](#): > > Could you share the entire stacktrace of the error you received? Where did the error happen? ```auto Traceback (most recent call last): File "temp.py", line 10, in class GstServer(GstRtspServer.RTSPServer): File "/home/bdonga/Documents/Pipeline/ray_env/lib/python3.8/site-packages/ray/worker.py", line 2276, in remote return _make_remote(args[0], {}) File "/home/bdonga/Documents/Pipeline/ray_env/lib/python3.8/site-packages/ray/worker.py", line 2147, in _make_remote return ray.actor.make_actor(function_or_class, options) File "/home/bdonga/Documents/Pipeline/ray_env/lib/python3.8/site-packages/ray/actor.py", line 1251, in make_actor _inject_tracing_into_class(Class) File "/home/bdonga/Documents/Pipeline/ray_env/lib/python3.8/site-packages/ray/util/tracing/tracing_helper.py", line 525, in _inject_tracing_into_class add_param_to_signature( File "/home/bdonga/Documents/Pipeline/ray_env/lib/python3.8/site-packages/ray/util/tracing/tracing_helper.py", line 102, in add_param_to_signature old_sig = inspect.signature(function) File "/usr/lib/python3.8/inspect.py", line 3093, in signature return Signature.from_callable(obj, follow_wrapped=follow_wrapped) File "/usr/lib/python3.8/inspect.py", line 2842, in from_callable return _signature_from_callable(obj, sigcls=cls, File "/usr/lib/python3.8/inspect.py", line 2405, in _signature_from_callable raise ValueError('callable {!r} is not supported by signature'.format(obj)) ValueError: callable gi.FunctionInfo(signal_handler_disconnect) is not supported by signature ``` ---
**Author:** ![jjyao](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.ray.io/jjyao/32/1799_2.png) [@jjyao](https://discuss.ray.io/u/jjyao)\ **Post date:** [September 6, 2022, 3:38am UTC](https://discuss.ray.io/t/error-while-creating-actor-class/7323/15 "2022-09-06T03:38:07Z")
Currently Ray requires that each actor method is supported by signature inspection for tracing purpose. To workaround this, instead of making GstServer a subclass of RTSPServer, could you create a RTSPServer as a class member so GstServer won’t automatically get all the methods from RTSPServer? ---
**Author:** ![jjyao](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.ray.io/jjyao/32/1799_2.png) [@jjyao](https://discuss.ray.io/u/jjyao)\ **Post date:** [September 6, 2022, 3:52am UTC](https://discuss.ray.io/t/error-while-creating-actor-class/7323/16 "2022-09-06T03:52:35Z")
I created [[Core] Actor methods will be modified for tracing even if tracing is not enabled. · Issue #28293 · ray-project/ray · GitHub](https://github.com/ray-project/ray/issues/28293) to fix the underling issue. ---
**Author:** ![krishna](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.ray.io/krishna/32/3146_2.png) [@krishna](https://discuss.ray.io/u/krishna)\ **Post date:** [September 6, 2022, 6:02am UTC](https://discuss.ray.io/t/error-while-creating-actor-class/7323/17 "2022-09-06T06:02:20Z")
We are receiving pickling issues when we make RTSPServer as a class member. Below is the stack trace: ```auto Traceback (most recent call last): File "/home/kandhavarapu/.local/lib/python3.10/site-packages/ray/_private/function_manager.py", line 461, in export_actor_class serialized_actor_class = pickle.dumps(Class) File "/home/kandhavarapu/.local/lib/python3.10/site-packages/ray/cloudpickle/cloudpickle_fast.py", line 73, in dumps cp.dump(obj) File "/home/kandhavarapu/.local/lib/python3.10/site-packages/ray/cloudpickle/cloudpickle_fast.py", line 620, in dump return Pickler.dump(self, obj) TypeError: cannot pickle 'GLibProxyModule' object The above exception was the direct cause of the following exception: Traceback (most recent call last): File "/home/kandhavarapu/projects/concor/warehouse/test.py", line 89, in server = GstServer.remote() File "/home/kandhavarapu/.local/lib/python3.10/site-packages/ray/actor.py", line 529, in remote return self._remote(args=args, kwargs=kwargs, **self._default_options) File "/home/kandhavarapu/.local/lib/python3.10/site-packages/ray/util/tracing/tracing_helper.py", line 387, in _invocation_actor_class_remote_span return method(self, args, kwargs, *_args, **_kwargs) File "/home/kandhavarapu/.local/lib/python3.10/site-packages/ray/actor.py", line 844, in _remote worker.function_actor_manager.export_actor_class( File "/home/kandhavarapu/.local/lib/python3.10/site-packages/ray/_private/function_manager.py", line 469, in export_actor_class raise TypeError(msg) from e TypeError: Could not serialize the actor class test.GstServer. __init__. Check https://docs.ray.io/en/master/ray-core/objects/serialization.html#troubleshooting for more information. ``` ---
**Author:** ![jjyao](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.ray.io/jjyao/32/1799_2.png) [@jjyao](https://discuss.ray.io/u/jjyao)\ **Post date:** [September 6, 2022, 10:56pm UTC](https://discuss.ray.io/t/error-while-creating-actor-class/7323/18 "2022-09-06T22:56:51Z")
Oh, that’s a bummer. Cloud you share your actor class definition? Want to see if we can workaround that. ---
**Author:** ![krishna](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.ray.io/krishna/32/3146_2.png) [@krishna](https://discuss.ray.io/u/krishna)\ **Post date:** [September 8, 2022, 1:04pm UTC](https://discuss.ray.io/t/error-while-creating-actor-class/7323/19 "2022-09-08T13:04:03Z")
Please find the actor class definition below: ```auto import gi import ray gi.require_version('Gst', '1.0') gi.require_version('GstRtspServer', '1.0') from gi.repository import Gst, GstRtspServer, GLib @ray.remote class GstServer(): def __init__ (self, **properties): Gst.init(None) self.server=GstRtspServer.RTSPServer(**properties) #super(GstServer, self). __init__ (**properties) self.loop = GLib.MainLoop() def start_streaming(self): self.loop.run() def stop_streaming(self): self.loop.quit() if __name__ == " __main__": obj = GstServer.remote() obj.start_streaming() ``` ---
**Author:** ![jjyao](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.ray.io/jjyao/32/1799_2.png) [@jjyao](https://discuss.ray.io/u/jjyao)\ **Post date:** [September 9, 2022, 5:36am UTC](https://discuss.ray.io/t/error-while-creating-actor-class/7323/20 "2022-09-09T05:36:46Z")
Hmm, I’m actually not sure why the code needs to pickle `GLibProxyModule`. Could you see which line of code triggers that (by commenting it out)? [Next page](https://discuss.ray.io/t/error-while-creating-actor-class/7323.md?page=2)