nodetool_additional_test.TestGetTraceProbability.test_invalid_value_not_changing_trace_probability assertion failure

[kbr-scylla]

This assertion failure is so unreadable

        assert re.search(message, str(error)), f"invalid_value={invalid_value} Expected: message"

first it should be {message} not message
ans second it should also print the str(error) because the failure report apparently truncates it...
But I digress

https://jenkins.scylladb.com/job/scylla-master/job/dtest-debug/295/testReport/junit/nodetool_additional_test/TestGetTraceProbability/Run_Dtest_Parallel_Cloud_Machines___FullDtest___full_split000___test_invalid_value_not_changing_trace_probability/

self = <nodetool_additional_test.TestGetTraceProbability object at 0x7fa3df28b550>
subtests = SubTests(ihook=<_pytest.config.compat.PathAwareHookProxy object at 0x7fa4ed175950>, suspend_capture_ctx=<bound method ...pture_fixture=None>>, request=<SubRequest 'subtests' for <Function test_invalid_value_not_changing_trace_probability>>)

    def test_invalid_value_not_changing_trace_probability(self, subtests):
        valid_value = 0.001
        for invalid_value in self.invalid_values_map:
            with subtests.test(invalid_value=invalid_value):
                set_node_probability(self.node1, valid_value)
>               self.set_invalid_trace_probability(node=self.node1, invalid_value=invalid_value, message=self.invalid_values_map[invalid_value])

nodetool_additional_test.py:2705: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

self = <nodetool_additional_test.TestGetTraceProbability object at 0x7fa3df28b550>
node = <ccmlib.scylla_node.ScyllaNode object at 0x7fa3cf7a8350>
invalid_value = 'a'
message = "(can not convert|error: the argument \\('a'\\) for option '--trace_probability' is invalid)"

    def set_invalid_trace_probability(self, node, invalid_value, message: str):
        with pytest.raises(NodetoolError) as error:
            node.nodetool(f"settraceprobability -- {invalid_value}")
>       assert re.search(message, str(error)), f"invalid_value={invalid_value} Expected: message"
E       AssertionError: invalid_value=a Expected: message
E       assert None
E        +  where None = <function search at 0x7fa4ee96d9e0>("(can not convert|error: the argument \\('a'\\) for option '--trace_probability' is invalid)", '<ExceptionInfo ToolError("Subprocess /jenkins/workspace/scylla-master/dtest-debug/scylla/.dtest/dtest-2jdn08vx/test/node1/bin/scylla ...--trace_probability\' is invalid\\n\\nTry --help.\\n; \\nstderr: WARNING: debug mode. Not for benchmarking or production\\n") tblen=3>')
E        +    where <function search at 0x7fa4ee96d9e0> = re.search
E        +    and   '<ExceptionInfo ToolError("Subprocess /jenkins/workspace/scylla-master/dtest-debug/scylla/.dtest/dtest-2jdn08vx/test/node1/bin/scylla ...--trace_probability\' is invalid\\n\\nTry --help.\\n; \\nstderr: WARNING: debug mode. Not for benchmarking or production\\n") tblen=3>' = str(<ExceptionInfo ToolError("Subprocess /jenkins/workspace/scylla-master/dtest-debug/scylla/.dtest/dtest-2jdn08vx/test/node1/bin/scylla ...--trace_probability' is invalid\n\nTry --help.\n; \nstderr: WARNING: debug mode. Not for benchmarking or production\n") tblen=3>)

nodetool_additional_test.py:2662: AssertionError

could be related to native nodetool somehow?

But it seems it appeared only in dtest-debug job for some reason.

Assigning to @denesb because it's nodetool and giving P4 label because it looks extremely unimportant (unless we really want to have green dtest-debug job)

[denesb]

The test fails because of the message printed by seastar when launching in debug mode:

WARNING: debug mode. Not for benchmarking or production

We changed ccm to filter this out of nodetool output, but maybe it doesn't work when nodetool exits with non-0 exit code, like in this test.

[denesb]

The problem is actually something else: str(error) ellipsizes the error message if it is too long, and for some reason now it also ellipsizes (cuts out) the part of the error message which we are matching for.