LTTng » Babeltrace

With babeltrace stable-1.4 python bindings :

$ ./lttng-iousagetop --debug /tmp/kernel/
Checking the trace for lost events...
net_if_receive_skbce: 0% [ ] ETA: --:--:--
Traceback (most recent call last):
File "/home/julien/src/analyzes/lttnganalyses/cli/command.py", line 73, in _run_step
fn()
File "/home/julien/src/analyzes/lttnganalyses/cli/command.py", line 355, in _run_analysis
self._analysis.begin_analysis(event)
File "/home/julien/src/analyzes/lttnganalyses/core/analysis.py", line 240, in begin_analysis
self._create_defless_period(evt)
File "/home/julien/src/analyzes/lttnganalyses/core/analysis.py", line 113, in _create_defless_period
period = core_period.Period(None, None, evt, None)
File "/home/julien/src/analyzes/lttnganalyses/core/period.py", line 552, in init
begin_evt_copy = core_event.Event(begin_evt)
File "/home/julien/src/analyzes/lttnganalyses/core/event.py", line 42, in init
self._copy_bt_event(bt_ev)
File "/home/julien/src/analyzes/lttnganalyses/core/event.py", line 55, in _copy_bt_event
field_value = bt_ev.field_with_scope(field_name, scope)
File "/usr/local/lib/python3.5/dist-packages/babeltrace.py", line 806, in field_with_scope
return field.value
File "/usr/local/lib/python3.5/dist-packages/babeltrace.py", line 1353, in value
value[member.name] = member.value
File "/usr/local/lib/python3.5/dist-packages/babeltrace.py", line 1348, in value
value = variant.value
File "/usr/local/lib/python3.5/dist-packages/babeltrace.py", line 1352, in value
member = _Definition(self._get_struct_field_at(i), self.scope)
File "/usr/local/lib/python3.5/dist-packages/babeltrace.py", line 1362, in scope
return self._s
AttributeError: '_Definition' object has no attribute '_s'
Error: Cannot run analysis: '_Definition' object has no attribute '_s'

It seems to produce this error when parsing this event:
[17:03:48.206456218] (+0.030903633) xenial-dev net_if_receive_skb: { cpu_id = 3 }, { skbaddr = 0xFFFF880138F66200, len = 88, name = "ens3", network_header_type = ( "_ipv4" : container = 1 ), network_header = { ipv4 = { version = 4, ihl = 5, tos = 16, tot_len = 88, id = 0xAD64, frag_off = 16384, ttl = 64, protocol = ( "_tcp" : container = 6 ), checksum = 0x179D, saddr_padding = { }, saddr = [ [0] = 192, [1] = 168, [2] = 122, [3] = 1 ], daddr_padding = { }, daddr = [ [0] = 192, [1] = 168, [2] = 122, [3] = 60 ], transport_header = { tcp = { source_port = 59466, dest_port = 22, seq = 3511938066, ack_seq = 4171945823, data_offset = 8, reserved = 0, flags = 0x18, window_size = 1866, checksum = 0x31F6, urg_ptr = 0 } } } } }

Other traces with this event definition do not produce the same problem.

I didn't find a way to capture similar problematic traces.

The problematic trace is attached to this bug report.