Anaconda3 on Mac OS: pexpect.exceptions.EOF: End Of File (EOF). Empty string style platform.

[andreok]

Hello,
I'm trying to run the gdl_kernel using Acaconda3 on Mac OS, with Python=3.7, pexpect=4.6 and notebook=5.7, but I'm getting the following error when I try to execute a cell:

...
[W 13:57:18.224 NotebookApp] 404 GET /nbextensions/widgets/notebook/js/extension.js?v=20250625135704 (127.0.0.1) 27.68ms referer=http://localhost:8888/notebooks/ECLIPSE-GDL.ipynb
Exception in callback <TaskWakeupMethWrapper object at 0x1095c0590>(<Future finis...igin\r\n\r\n'>)
handle: <Handle <TaskWakeupMethWrapper object at 0x1095c0590>(<Future finis...igin\r\n\r\n'>)>
Traceback (most recent call last):
  File "/opt/anaconda3/envs/gdl/lib/python3.7/asyncio/events.py", line 88, in _run
    self._context.run(self._callback, *self._args)
RuntimeError: Cannot enter into task <Task pending coro=<HTTP1ServerConnection._server_request_loop() running at /opt/anaconda3/envs/gdl/lib/python3.7/site-packages/tornado/http1connection.py:825> wait_for=<Future finished result=b'GET /api/co...rigin\r\n\r\n'> cb=[IOLoop.add_future.<locals>.<lambda>() at /opt/anaconda3/envs/gdl/lib/python3.7/site-packages/tornado/ioloop.py:687]> while another task <Task pending coro=<KernelManager._async_start_kernel() running at /opt/anaconda3/envs/gdl/lib/python3.7/site-packages/jupyter_client/manager.py:82>> is being executed.
[I 13:57:18.678 NotebookApp] Kernel started: 1d89e691-4f27-4bd3-ade9-a5a72e108b51
Traceback (most recent call last):
  File "/opt/anaconda3/envs/gdl/lib/python3.7/site-packages/pexpect/expect.py", line 111, in expect_loop
    incoming = spawn.read_nonblocking(spawn.maxread, timeout)
  File "/opt/anaconda3/envs/gdl/lib/python3.7/site-packages/pexpect/pty_spawn.py", line 485, in read_nonblocking
    return super(spawn, self).read_nonblocking(size)
  File "/opt/anaconda3/envs/gdl/lib/python3.7/site-packages/pexpect/spawnbase.py", line 176, in read_nonblocking
    raise EOF('End Of File (EOF). Empty string style platform.')
pexpect.exceptions.EOF: End Of File (EOF). Empty string style platform.

During handling of the above exception, another exception occurred:
...
Traceback (most recent call last):
  File "/opt/anaconda3/envs/gdl/lib/python3.7/runpy.py", line 193, in _run_module_as_main
    "__main__", mod_spec)
  File "/opt/anaconda3/envs/gdl/lib/python3.7/runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "/opt/anaconda3/envs/gdl/lib/python3.7/site-packages/gdl_kernel.py", line 209, in <module>
    IPKernelApp.launch_instance(kernel_class=GDLKernel)
  File "/opt/anaconda3/envs/gdl/lib/python3.7/site-packages/traitlets/config/application.py", line 991, in launch_instance
    app.initialize(argv)
  File "/opt/anaconda3/envs/gdl/lib/python3.7/site-packages/traitlets/config/application.py", line 113, in inner
    return method(app, *args, **kwargs)
  File "/opt/anaconda3/envs/gdl/lib/python3.7/site-packages/ipykernel/kernelapp.py", line 681, in initialize
    self.init_kernel()
  File "/opt/anaconda3/envs/gdl/lib/python3.7/site-packages/ipykernel/kernelapp.py", line 541, in init_kernel
    user_ns=self.user_ns,
  File "/opt/anaconda3/envs/gdl/lib/python3.7/site-packages/traitlets/config/configurable.py", line 552, in instance
    inst = cls(*args, **kwargs)
  File "/opt/anaconda3/envs/gdl/lib/python3.7/site-packages/gdl_kernel.py", line 50, in __init__
    self._start_gdl()
  File "/opt/anaconda3/envs/gdl/lib/python3.7/site-packages/gdl_kernel.py", line 70, in _start_gdl
    self.gdlwrapper = replwrap.REPLWrapper(self._child,u"GDL> ",None)
  File "/opt/anaconda3/envs/gdl/lib/python3.7/site-packages/pexpect/replwrap.py", line 55, in __init__
    self._expect_prompt()
  File "/opt/anaconda3/envs/gdl/lib/python3.7/site-packages/pexpect/replwrap.py", line 66, in _expect_prompt
    timeout=timeout)
  File "/opt/anaconda3/envs/gdl/lib/python3.7/site-packages/pexpect/spawnbase.py", line 418, in expect_exact
    return exp.expect_loop(timeout)
  File "/opt/anaconda3/envs/gdl/lib/python3.7/site-packages/pexpect/expect.py", line 117, in expect_loop
    return self.eof(e)
  File "/opt/anaconda3/envs/gdl/lib/python3.7/site-packages/pexpect/expect.py", line 63, in eof
    raise EOF(msg)
pexpect.exceptions.EOF: End Of File (EOF). Empty string style platform.
<pexpect.pty_spawn.spawn object at 0x104373690>
command: /usr/local/bin/gdl
args: [b'/usr/local/bin/gdl', b'--use-wx']
buffer (last 100 chars): ''
before (last 100 chars): '/usr/local/bin/gdl: --use-wx option not recognized.\r\n'
after: <class 'pexpect.exceptions.EOF'>
match: None
match_index: None
exitstatus: None
flag_eof: True
pid: 34394
child_fd: 65
closed: False
timeout: 300
delimiter: <class 'pexpect.exceptions.EOF'>
logfile: None
logfile_read: None
logfile_send: None
maxread: 2000
ignorecase: False
searchwindowsize: None
delaybeforesend: 0.05
delayafterclose: 0.1
delayafterterminate: 0.1
searcher: searcher_string:
    0: 'GDL> '
    1: '[PEXPECT_PROMPT+'

Searching for this error message I found a comment on the API Overview page for Pexpect that describes this exception: https://pexpect.readthedocs.io/en/stable/overview.html#exceptions
Thanks,
Andre

[andreok]

The error seems to be related to the '--use-wx' option on gdl startup, that's not recognized:

...
command: /usr/local/bin/gdl
args: [b'/usr/local/bin/gdl', b'--use-wx']
buffer (last 100 chars): ''
before (last 100 chars): '/usr/local/bin/gdl: --use-wx option not recognized.\r\n'
...

I tried using WXWIDGETS=ON for the gdl build but it keeps returning this error, since gdl only accepts a '--no-use-wx' option, instead:

$ gdl -h
Usage: gdl [ OPTIONS ] [ batch_file ... ]
Start the GDL interpreter (incremental compiler)

GDL options:
  --help (-h)        display this message
  --version (-V, -v) show version information
  --fakerelease X.y  pretend that !VERSION.RELEASE is X.y
  --trace-old-syntax print lines that do not adhere with modern IDL, where "()" are for functions and "[]" are for arrays.
  --MAC              Graphic device will be called 'MAC' on MacOSX. (default: 'X')
  [--no-use-wx | -X] Tells GDL not to use WxWidgets graphics and resort to X11 (if available).
                     Also enabled by setting the environment variable GDL_DISABLE_WX_PLOTS to a non-null value.
  --notebook         Force SVG-only device, used only when GDL is a Python Notebook Kernel.
  --widget-compat    Tells GDL to use a default (rather ugly) fixed pitch font for compatiblity with IDL widgets.
                     Also enabled by setting the environment variable GDL_WIDGET_COMPAT to a non-null value.
                     Using this option may render some historical widgets more readable (as they are based on fixed sizes).
  --no-dSFMT         Tells GDL not to use double precision SIMD oriented Fast Mersenne Twister(dSFMT) for random doubles.
                     Also disable by setting the environment variable GDL_NO_DSFMT to a non-null value.
  --with-eigen-transpose lets GDL use Eigen::transpose and related functions instead of our accelerated transpose function. Normally slower.
  --smart-tpool      switch to a mode where the number of threads is adaptive (experimental). Should enable better perfs on many core machines.
  --silent           Supresses some messages (mainly "Compiled Module XXX" .

IDL-compatible options:
  -arg value tells COMMAND_LINE_ARGS() to report
             the following argument (may be specified more than once)
  -args ...  tells COMMAND_LINE_ARGS() to report 
             all following arguments
  -e value   execute given statement and exit (last occurrence taken into account only,
             executed after startup file, may not be specified together with batch files)
  -pref=/path/to/params_file  loads the specified preference file
  -quiet (--quiet, -q) suppress welcome messages

Homepage: https://gnudatalanguage.github.io

Maybe it should use the '--notebook' instead of the '--use-wx'?