intermittent functional test failure in wallet_bumpfee #17716

https://travis-ci.org/bitcoin/bitcoin/jobs/623304089#L8090

 test  2019-12-10T18:32:57.082000Z TestFramework (ERROR): Assertion failed 
                                   Traceback (most recent call last):
                                     File "/home/travis/build/bitcoin/bitcoin/build/bitcoin-s390x-unknown-linux-gnu/test/functional/test_framework/test_framework.py", line 112, in main
                                       self.run_test()
                                     File "/home/travis/build/bitcoin/bitcoin/build/bitcoin-s390x-unknown-linux-gnu/test/functional/wallet_bumpfee.py", line 90, in run_test
                                       test_small_output_with_feerate_succeeds(rbf_node, dest_address)
                                     File "/home/travis/build/bitcoin/bitcoin/build/bitcoin-s390x-unknown-linux-gnu/test/functional/wallet_bumpfee.py", line 224, in test_small_output_with_feerate_succeeds
                                       assert_equal(len(input_list), 1)
                                     File "/home/travis/build/bitcoin/bitcoin/build/bitcoin-s390x-unknown-linux-gnu/test/functional/test_framework/util.py", line 46, in assert_equal
                                       raise AssertionError("not(%s)" % " == ".join(str(arg) for arg in (thing1, thing2) + args))
                                   AssertionError: not(16 == 1)

Another one: https://travis-ci.org/bitcoin/bitcoin/jobs/660197025#L4359

The test has been written in d08becff853 and 38516f90784 by @instagibbs

For me it is hard to dig through the combined logs, because the test has zero logging (Other than self.log.info("Running tests")). It would be nice if at least this function got a debug or info log statement to explain what is going on.

I'll take a look this week.

@MarcoFalke I believe I've figured it out. Apologies for the sloppy test: https://github.com/bitcoin/bitcoin/pull/18311