tests/integration/interactive_build.py::test_failed_build_log[interactive/failed-build.bst] fails in non interactive mode

[nathanwilliams-ct]

See: https://gitlab.com/BuildStream/buildstream-docker-images/-/merge_requests/238#note_3715370970

TLDR from matrix: CI failing because the latest fedora 43 container had python 3.14.2, and now it's 3.14.7, and buildstream doesn't work with 3.14.7?
Looks like !240 (merged) is potential fix, to later fix Buildstream compatibility with 3.14.7

Which means this MR is blocked until !240 (merged) or other MR fixes the CI job.

Interesting running the test locally against Buildstream master, we don't hit the same failure with python 3.14.7
$ uvx --python 3.14.7 tox -e py314 run -- tests/integration/interactive_build.py::test_failed_build_log --no-cov --integration
snip setup
===================================================================================== test session starts ======================================================================================
platform linux -- Python 3.14.7, pytest-9.0.3, pluggy-1.6.0 -- /var/home/nathanwilliams/buildstream/.tox/py314/bin/python
cachedir: .tox/py314/.pytest_cache
rootdir: /var/home/nathanwilliams/buildstream
configfile: setup.cfg
plugins: xdist-3.8.0, timeout-2.4.0, env-1.6.0, datafiles-3.0.1, cov-7.1.0
timeout: 1800.0s
timeout method: signal
timeout func_only: False
collected 1 item

tests/integration/interactive_build.py::test_failed_build_log[interactive/failed-build.bst] PASSED [100%]

===================================================================================== slowest 20 durations =====================================================================================
9.05s call tests/integration/interactive_build.py::test_failed_build_log[interactive/failed-build.bst]
0.08s setup tests/integration/interactive_build.py::test_failed_build_log[interactive/failed-build.bst]

(1 durations < 0.005s hidden. Use -vv to show these durations.)
====================================================================================== 1 passed in 9.18s =======================================================================================
snip teardown
compared to: https://gitlab.com/BuildStream/buildstream-docker-images/-/jobs/16010720616#L3798

Interesting. Did you try it without the console? (e.g. tox ... | cat)

Dead:
$ uvx --python 3.14.7 tox -e py314 run -- tests/integration/interactive_build.py::test_failed_build_log --no-cov --integration | cat
snip setup
============================= test session starts ==============================
platform linux -- Python 3.14.7, pytest-9.0.3, pluggy-1.6.0 -- /var/home/nathanwilliams/buildstream/.tox/py314/bin/python
cachedir: .tox/py314/.pytest_cache
rootdir: /var/home/nathanwilliams/buildstream
configfile: setup.cfg
plugins: xdist-3.8.0, timeout-2.4.0, env-1.6.0, datafiles-3.0.1, cov-7.1.0
timeout: 1800.0s
timeout method: signal
timeout func_only: False
collecting ... collected 1 item

tests/integration/interactive_build.py::test_failed_build_log[interactive/failed-build.bst] FAILED [100%]

=================================== FAILURES ===================================
_____________ test_failed_build_log[interactive/failed-build.bst] ______________

element_name = 'interactive/failed-build.bst'
build_session = <pexpect.pty_spawn.spawn object at 0x7fcd1ccef8c0>

@pytest.mark.skipif(not HAVE_SANDBOX, reason="Only available with a functioning sandbox")
@pytest.mark.datafiles(DATA_DIR)
@pytest.mark.parametrize("element_name", ["interactive/failed-build.bst"])
def test_failed_build_log(element_name, build_session):
 build_session.expect_exact("Choice: [continue]:", timeout=PEXPECT_TIMEOUT_LONG)
 build_session.sendline("log")

 # Send a few carriage returns to get to the end of the pager
 build_session.sendline(os.linesep * 20)

 # Assert that we got something from the logs
 build_session.expect("FAILURE interactive/failed-build.bst: Running (build-)?commands")

 # Quit the pager
 build_session.send("q")
 # Quit the session

 build_session.expect_exact("Choice: [continue]:")

tests/integration/interactive_build.py:108:

---

.tox/py314/lib/python3.14/site-packages/pexpect/spawnbase.py:432: in expect_exact
return exp.expect_loop(timeout)
^^^^^^^^^^^^^^^^^^^^^^^^
.tox/py314/lib/python3.14/site-packages/pexpect/expect.py:179: in expect_loop
return self.eof(e)
^^^^^^^^^^^

---

self = <pexpect.expect.Expecter object at 0x7fcd1cb8ca50>
err = EOF('End Of File (EOF). Exception style platform.')

def eof(self, err=None):
 spawn = self.spawn

 spawn.before = spawn._before.getvalue()
 spawn._buffer = spawn.buffer_type()
 spawn._before = spawn.buffer_type()
 spawn.after = EOF
 index = self.searcher.eof_index
 if index >= 0:
 spawn.match = EOF
 spawn.match_index = index
 return index
 else:
 spawn.match = None
 spawn.match_index = None
 msg = str(spawn)
 msg += '\nsearcher: %s' % self.searcher
 if err is not None:
 msg = str(err) + '\n' + msg

 exc = EOF(msg)
 exc.__cause__ = None # in Python 3.x we can use "raise exc from None"

 raise exc

E pexpect.exceptions.EOF: End Of File (EOF). Exception style platform.
E <pexpect.pty_spawn.spawn object at 0x7fcd1ccef8c0>
E command: /var/home/nathanwilliams/buildstream/.tox/py314/bin/bst
E args: ['/var/home/nathanwilliams/buildstream/.tox/py314/bin/bst', '--directory', '/var/home/nathanwilliams/buildstream/.tox/py314/tmp/test_failed_build_log_interact0', '--config', '/var/home/nathanwilliams/buildstream/.tox/py314/tmp/test_failed_build_log_interact0/buildstream.conf', '--no-colors', 'build', 'interactive/failed-build.bst']
E buffer (last 100 chars): b''
E before (last 100 chars): b' Queue: processed 3, skipped 0, failed 0 \r\n Build Queue: processed 2, skipped 0, failed 1 \r\n\r\n\r\nq'
E after: <class 'pexpect.exceptions.EOF'>
E match: None
E match_index: None
E exitstatus: None
E flag_eof: True
E pid: 67734
E child_fd: 13
E closed: False
E timeout: 30
E delimiter: <class 'pexpect.exceptions.EOF'>
E logfile: None
E logfile_read: None
E logfile_send: None
E maxread: 2000
E ignorecase: False
E searchwindowsize: None
E delaybeforesend: 0.05
E delayafterclose: 0.1
E delayafterterminate: 0.1
E searcher: searcher_string:
E 0: b'Choice: [continue]:'

.tox/py314/lib/python3.14/site-packages/pexpect/expect.py:122: EOF
============================= slowest 20 durations =============================
8.79s call tests/integration/interactive_build.py::test_failed_build_log[interactive/failed-build.bst]
0.09s setup tests/integration/interactive_build.py::test_failed_build_log[interactive/failed-build.bst]

(1 durations < 0.005s hidden. Use -vv to show these durations.)
=========================== short test summary info ============================
FAILED tests/integration/interactive_build.py::test_failed_build_log[interactive/failed-build.bst]
============================== 1 failed in 9.01s ===============================
snip teardown

Fails same way in 3.14.6, 3.14.5, 3.14.4, 3.14.3 and 3.14.2
A change in buildstream?

[nathanwilliams-ct]

@abderrahim wrote:

Probably something for @juergbi . I suspect it's a pre-existing bug in the test uncovered by https://github.com/apache/buildstream/commit/4a2fe3783beffe91b31f096c83f38a5166f0427f