Unexpected, flakey, test failure

[krader1961]

While working on issue #1132 I ran the unit tests and observed the following unexpected failure. Repeating the test succeeded. The change I made to implement a printf builtin should not (can not?) affect the behavior of the failing unit test. Since I've never seen this failure before, and cannot reproduce the failure, it is presumably an extremely rare race condition.

--- FAIL: TestLocationAddon_Workspace (0.35s)
    listing_nonwindows_test.go:73: Wanted buffer not shown
    listing_nonwindows_test.go:73: Want: Width = 50, Dot = (0, 11)
        ┌──────────────────────────────────────────────────┐
        │~/ws1/bin> $                                      │
        └──────────────────────────────────────────────────┘
    listing_nonwindows_test.go:73: Last buffer: Width = 50, Dot = (1, 11)
        ┌──────────────────────────────────────────────────┐
        │~/ws1/tmp> $                                      │
        │ LOCATION  $                                      │
        │ 10 ws/bin                                        │
        │ 10 /usr/bin$                                     │
        └──────────────────────────────────────────────────┘
FAIL
coverage: 83.5% of statements
FAIL    github.com/elves/elvish/pkg/edit        6.645s

[krader1961]

I also regularly see what I think is essentially the same unit test failure. Such as this example that occurred on Linux and BSD a few minutes ago while testing an unrelated change:

--- FAIL: TestNavigation_EnterDoesNothingInEmptyDir (0.34s)
    navigation_test.go:135: Wanted buffer not shown
    navigation_test.go:135: Want: Width = 50, Dot = (0, 10)
        ┌──────────────────────────────────────────────────┐
        │~/d/e> put$                                       │
        │ NAVIGATING  $                                    │
        │ a                        $                       │
        │ e    $                                           │
        └──────────────────────────────────────────────────┘
    navigation_test.go:135: Last buffer: Width = 50, Dot = (0, 7)
        ┌──────────────────────────────────────────────────┐
        │~/d> pu$                                          │
        │ NAVIGATING  $                                    │
        │ a                        $                       │
        │ e    $                                           │
        └──────────────────────────────────────────────────┘
FAIL
FAIL    src.elv.sh/pkg/edit     6.428s

[krader1961]

Closing because I see many failures of this type on an infrequent basis and it's not clear this issue is actionable. There are lots of issues that are more important to resolve than an infrequent unit test failure due to an apparent race of some sort.