t/integration/failure_cases.t may fail

On some of my smokers (with Test2-Harness-1.000050):

    # Failed test 'Exit Value Check'
    # at t/integration/failure_cases.t line 42.
    # +-----+---------+-------+-----+
    # | GOT | OP      | CHECK | LNs |
    # +-----+---------+-------+-----+
    # | 256 | FALSE() | FALSE | 42  |
    # +-----+---------+-------+-----+
    # Command = /usr/perl5.30.0p/bin/perl /usr/home/cpansand/.cpan/build/2021042717/Test2-Harness-1.000050-1/scripts/yath -D/usr/home/cpansand/.cpan/build/2021042717/Test2-Harness-1.000050-1/blib/lib test -I/usr/home/cpansand/.cpan/build/2021042717/Test2-Harness-1.000050-1/blib/lib t/integration/failure_cases/parse_error.tx
    # Exit = 256
    # ==== Output ====
    # 
    # The following jobs failed:
    # +------------------------------------+------------------------------------+
    # | Job ID                             | Test File                          |
    # +------------------------------------+------------------------------------+
    # | FD4EB560-A77C-11EB-A60C-98BEFE207F | t/integration/failure_cases/parse_ |
    # | 05                                 | error.tx                           |
    # +------------------------------------+------------------------------------+
    # 
    #                                 Yath Result Summary
    # -----------------------------------------------------------------------------------
    #      Fail Count: 1
    #      File Count: 1
    # Assertion Count: 0
    #       Wall Time: 0.41 seconds
    #        CPU Time: 0.69 seconds (usr: 0.19s | sys: 0.03s | cusr: 0.36s | csys: 0.11s)
    #       CPU Usage: 168%
    #     -->  Result: FAILED  <--
    # 
    # 
    # ========

# Failed test 'yath test t/integrat[...]e_error.tx'
# at t/integration/failure_cases.t line 22.
# Seeded srand with seed '20210427' from local date.
t/integration/failure_cases.t ............ 
Dubious, test returned 1 (wstat 256, 0x100)
Failed 1/28 subtests 

Start by running t/integration/failure_cases.t and inspect line 42 together with t/integration/failure_cases/parse_error.tx. Reproduce the reported exit value of 256 on an affected smoker and compare it with the test's expected result; done means the failure case completes without the reported subtest failure.