No longer able to use pudb with Tempest

[rh-jelabarre]

At one time I was able to use pudb as a debugger for Tempest testcases for testing OpenStack. But over the past half year or more it will no longer work. I will install pudb with "sudo python3 -m pip install pudb" (I have to use sudo, as even with the '--user' switch the install insists on installing packages to /usr/) and put "import pudb;pudb.set_trace()" at the desired breakpoint (usually the beginning of the definition for the particular testcase).

The debug process will fail with this traceback:

Captured traceback:

    b'Traceback (most recent call last):'
    b'  File "/usr/local/lib/python3.6/site-packages/tempest/api/compute/servers/test_server_actions.py", line 401, in test_resize_server_confirm_from_stopped'
    b'    self._test_resize_server_confirm(self.server_id, stop=True)'
    b'  File "/usr/local/lib/python3.6/site-packages/tempest/api/compute/servers/test_server_actions.py", line 321, in _test_resize_server_confirm'
    b'    def _test_resize_server_confirm(self, server_id, stop=False):'
    b'  File "/usr/lib64/python3.6/bdb.py", line 53, in trace_dispatch'
    b'    return self.dispatch_call(frame, arg)'
    b'  File "/usr/lib64/python3.6/bdb.py", line 85, in dispatch_call'
    b'    self.user_call(frame, arg)'
    b'  File "/usr/local/lib/python3.6/site-packages/pudb/debugger.py", line 433, in user_call'
    b'    self.interaction(frame)'
    b'  File "/usr/local/lib/python3.6/site-packages/pudb/debugger.py", line 422, in interaction'
    b'    show_exc_dialog=show_exc_dialog)'
    b'  File "/usr/local/lib/python3.6/site-packages/pudb/debugger.py", line 2412, in call_with_ui'
    b'    return f(*args, **kwargs)'
    b'  File "/usr/local/lib/python3.6/site-packages/pudb/debugger.py", line 2703, in interaction'
    b'    self.event_loop()'
    b'  File "/usr/local/lib/python3.6/site-packages/pudb/debugger.py", line 2660, in event_loop'
    b'    keys = self.screen.get_input()'
    b'  File "/usr/local/lib/python3.6/site-packages/urwid/raw_display.py", line 343, in get_input'
    b'    keys, raw = self.parse_input(None, None, self.get_available_raw_input())'
    b'  File "/usr/local/lib/python3.6/site-packages/urwid/raw_display.py", line 449, in get_available_raw_input'
    b'    codes = self._get_gpm_codes() + self._get_keyboard_codes()'
    b'  File "/usr/local/lib/python3.6/site-packages/urwid/raw_display.py", line 523, in _get_keyboard_codes'
    b'    code = self._getch_nodelay()'
    b'  File "/usr/local/lib/python3.6/site-packages/urwid/raw_display.py", line 661, in _getch_nodelay'
    b'    return self._getch(0)'
    b'  File "/usr/local/lib/python3.6/site-packages/urwid/raw_display.py", line 571, in _getch'
    b'    return ord(os.read(fd, 1))'
    b'TypeError: ord() expected a character, but string of length 0 found'

I haven't found any useful results searching on those error messages.

I tried running the pudb "try-the-debugger.sh" script (and the debug_me.py file) from the repository here, and the UI comes up just fine.  So somewhere there must be a conflict with Tempest or OpenStack hanging up the process.

[inducer]

Are you sure your stdin is attached to a terminal? It looks like it's trying to read input and getting an EOF. Maybe try the remote debugging facility if that continues to be a problem?