Re: [PATCH v2 7/7] t/helper/simple-ipc: convert test-simple-ipc to use start_bg_command

On Sat, 13 Nov 2021 at 19:11, Ramsay Jones [off-list ref] wrote:

On 10/11/2021 12:27, Johannes Schindelin wrote:
[snip]

quoted

quoted

I cannot give the change any better test than they can, and it is
their platform to improve, or break by accident while trying to do
so.

Right. I tested this as well as I could, via the `--stress` option, and am
fairly confident that it is correct. Since the patch touches only
`simply-ipc` code, the only test that could possibly affected is t0052,
and it passes with `--stress` over here (when it failed without the
patch).

Ciao,
Dscho

P.S.: in case you wondered, no, I did not run the entire test suite. With
the performance characteristics of the POSIX emulation provided by the
Cygwin runtime, this would simply take too long. It's not the first time I
wish our test suite was more efficient, across _all_ supported platforms.

[I seem to have lost Adam's reply about this now being Hunky-Dory, but ...]

I ran the test-suite on -rc2 on thursday night (note _not_ rc2 + this patch)
and it deadlocked on me; I didn't notice for 4 hours, so (in the early hours)
I simply Ctl+C-ed it and went to bed. I haven't had the test-suite deadlock
for many many years - I've been spoilt! ;-)

I tried -rc2 again last night; this time it finished, but I gained another
test failure: t0301-credential-cache.sh. I have _never_ had this test fail
before, so that was unexpected. :(

[Yes, t0052-simple-ipc.sh failed as expected, since this patch was not
applied].

Also, I was half expecting a small speed-up due to the new pipe code in
v3.3.2 of the cygwin dll, but it actually took an hour longer than normal. :(

The only change to my setup, between -rc1 and -rc2, was the cygwin update
to v3.3.2, so this may point to some more fallout from the new pipe code
(maybe?).

Anyway, I haven't even looked at the new failure (see below), which we will
probably not have time to fix before release, so I am just now building
current master (v2.34.0-rc2-16-g5a73c6bdc7) to give that a try. (So, I won't
have anything to report until tomorrow).

I'm seeing the same failure. It isn't caused by a change in Git --
I've rebuilt and re-run the test on old versions where that test was
passing, and it's now failing -- so this is clearly something in the
Cygwin environment. I've not investigated further, but it's clearly
caused by a Cygwin change rather than a Git change, so I don't think
there's any reason to hold up the Git release.

(I should probably report it on the Cygwin mailing list, but I haven't
got around to that yet...)