test_time: test_monotonic() failed on AMD64 FreeBSD 10-STABLE Non-Debug 3.7

[vstinner]

BPO	36454
Nosy	@vstinner, @koobs, @miss-islington
PRs	bpo-36454: Fix test_time.test_monotonic() #12929 [3.7] bpo-36454: Fix test_time.test_monotonic() (GH-12929) #12930

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

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GitHub fields:

assignee = None
closed_at = <Date 2019-04-23.23:46:23.783>
created_at = <Date 2019-03-28.01:54:53.642>
labels = ['3.8', '3.7', 'tests']
title = 'test_time: test_monotonic() failed on AMD64 FreeBSD 10-STABLE Non-Debug 3.7'
updated_at = <Date 2019-04-24.10:51:29.845>
user = 'https://github.com/vstinner'

bugs.python.org fields:

activity = <Date 2019-04-24.10:51:29.845>
actor = 'koobs'
assignee = 'none'
closed = True
closed_date = <Date 2019-04-23.23:46:23.783>
closer = 'vstinner'
components = ['Tests']
creation = <Date 2019-03-28.01:54:53.642>
creator = 'vstinner'
dependencies = []
files = []
hgrepos = []
issue_num = 36454
keywords = ['patch']
message_count = 3.0
messages = ['339002', '340744', '340745']
nosy_count = 3.0
nosy_names = ['vstinner', 'koobs', 'miss-islington']
pr_nums = ['12929', '12930']
priority = 'normal'
resolution = 'fixed'
stage = 'resolved'
status = 'closed'
superseder = None
type = None
url = 'https://bugs.python.org/issue36454'
versions = ['Python 3.7', 'Python 3.8']

[vstinner]

AMD64 FreeBSD 10-STABLE Non-Debug 3.7:
https://buildbot.python.org/all/#/builders/170/builds/354

======================================================================
FAIL: test_monotonic (test.test_time.TimeTestCase)
----------------------------------------------------------------------

Traceback (most recent call last):
  File "/usr/home/buildbot/python/3.7.koobs-freebsd10.nondebug/build/Lib/test/test_time.py", line 474, in test_monotonic
    self.assertTrue(0.45 <= dt <= 1.0, dt)
AssertionError: False is not true : 1.0372954378835857

Extract of the test:

    def test_monotonic(self):
        ...

        # monotonic() includes time elapsed during a sleep
        t1 = time.monotonic()
        time.sleep(0.5)
        t2 = time.monotonic()
        dt = t2 - t1
        self.assertGreater(t2, t1)
        # Issue python/cpython#64300: On some Windows machines, dt may be slightly low
        self.assertTrue(0.45 <= dt <= 1.0, dt)

    ...

IMHO the test is too strict. It should not test the maximum value of dt, only the minimum.

[vstinner]

New changeset d246a67 by Victor Stinner in branch 'master':
bpo-36454: Fix test_time.test_monotonic() (GH-12929)
d246a67

[miss-islington]

New changeset e1a6cf2 by Miss Islington (bot) in branch '3.7':
bpo-36454: Fix test_time.test_monotonic() (GH-12929)
e1a6cf2