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pythondebuggingtensorflowncurses

Why do I get "_curses.error: cbreak() returned ERR" when using TensorFlow CLI Debugger?


I am trying to use the TensorFlow CLI debugger in order to identify the operation which is causing a NaN during training of a network, but when I try to run the code I get an error:

_curses.error: cbreak() returned ERR

I'm running the code on an Ubuntu server, which I'm connecting to via SSH, and have tried to follow this tutorial.

I have tried using tf.add_check_numerics_ops(), but the layers in the network include while loops so are not compatible. This is the section of code where the error is being raised:

import tensorflow as tf
from tensorflow.python import debug as tf_debug
...
#Prepare data
train_data, val_data, test_data = dataset.prepare_datasets(model_config)

sess = tf.Session()
sess = tf_debug.LocalCLIDebugWrapperSession(sess)

# Create iterators
handle = tf.placeholder(tf.string, shape=[])
iterator = tf.data.Iterator.from_string_handle(handle, train_data.output_types, train_data.output_shapes)
mixed_spec, voice_spec, mixed_audio, voice_audio = iterator.get_next()

training_iterator = train_data.make_initializable_iterator()
validation_iterator = val_data.make_initializable_iterator()
testing_iterator = test_data.make_initializable_iterator()

training_handle = sess.run(training_iterator.string_handle())
...

and the full error is:

Traceback (most recent call last):
  File "main.py", line 64, in <module>
    @ex.automain
  File "/home/enterprise.internal.city.ac.uk/acvn728/.local/lib/python3.5/site-packages/sacred/experiment.py", line 137, in automain
    self.run_commandline()
  File "/home/enterprise.internal.city.ac.uk/acvn728/.local/lib/python3.5/site-packages/sacred/experiment.py", line 260, in run_commandline
    return self.run(cmd_name, config_updates, named_configs, {}, args)
  File "/home/enterprise.internal.city.ac.uk/acvn728/.local/lib/python3.5/site-packages/sacred/experiment.py", line 209, in run
    run()
  File "/home/enterprise.internal.city.ac.uk/acvn728/.local/lib/python3.5/site-packages/sacred/run.py", line 221, in __call__
    self.result = self.main_function(*args)
  File "/home/enterprise.internal.city.ac.uk/acvn728/.local/lib/python3.5/site-packages/sacred/config/captured_function.py", line 46, in captured_function
    result = wrapped(*args, **kwargs)
  File "main.py", line 95, in do_experiment
    training_handle = sess.run(training_iterator.string_handle())
  File "/home/enterprise.internal.city.ac.uk/acvn728/.local/lib/python3.5/site-packages/tensorflow/python/debug/wrappers/framework.py", line 455, in run
    is_callable_runner=bool(callable_runner)))
  File "/home/enterprise.internal.city.ac.uk/acvn728/.local/lib/python3.5/site-packages/tensorflow/python/debug/wrappers/local_cli_wrapper.py", line 255, in on_run_start
    self._run_start_response = self._launch_cli()
  File "/home/enterprise.internal.city.ac.uk/acvn728/.local/lib/python3.5/site-packages/tensorflow/python/debug/wrappers/local_cli_wrapper.py", line 431, in _launch_cli
    title_color=self._title_color)
  File "/home/enterprise.internal.city.ac.uk/acvn728/.local/lib/python3.5/site-packages/tensorflow/python/debug/cli/curses_ui.py", line 492, in run_ui
    self._screen_launch(enable_mouse_on_start=enable_mouse_on_start)
  File "/home/enterprise.internal.city.ac.uk/acvn728/.local/lib/python3.5/site-packages/tensorflow/python/debug/cli/curses_ui.py", line 445, in _screen_launch
    curses.cbreak()
_curses.error: cbreak() returned ERR

I'm pretty new to using Ubuntu (and TensorFlow), but as far as I can tell the server does have ncurses installed, which should allow the required curses based interface:

acvn728@america:~/MScFinalProject$ dpkg -l '*ncurses*' | grep '^ii'
ii  libncurses5:amd64  6.0+20160213-1ubuntu1 amd64        shared libraries for terminal handling
ii  libncursesw5:amd64 6.0+20160213-1ubuntu1 amd64        shared libraries for terminal handling (wide character support)
ii  ncurses-base       6.0+20160213-1ubuntu1 all          basic terminal type definitions
ii  ncurses-bin        6.0+20160213-1ubuntu1 amd64        terminal-related programs and man pages
ii  ncurses-term       6.0+20160213-1ubuntu1 all          additional terminal type definitions

Solution

  • Problem solved! The solution was to change

    sess = tf_debug.LocalCLIDebugWrapperSession(sess)
    

    to

    sess = tf_debug.LocalCLIDebugWrapperSession(sess, ui_type="readline")
    

    This is similar to the solution to this question, but I I think it is important to note that they are different because a) it refers to a different function and a different API and b) I wasn't trying to run from an IDE, as mentioned in that solution.