On Fri, Feb 08, 2019 at 09:32:32AM +0100, Johannes Schindelin wrote: > Team, > > On Mon, 6 Aug 2018, SZEDER Gábor wrote: > > > [Resending with Clemens' last used email address. > > Clemens, please consider sending a patch to update our .mailmap file.] > > > > > > On Mon, Aug 6, 2018 at 5:11 PM SZEDER Gábor <szeder.dev@xxxxxxxxx> wrote: > > > > > > Travis CI changed its default OSX image to use XCode 9.4 on 2018-07-31 > > > [1]. Since then OSX build jobs fail rather frequently because of a > > > SIGPIPE in the tests 'fetch notices corrupt pack' or 'fetch notices > > > corrupt idx' in 't5570-git-daemon.sh' [2]. I think this is a symptom > > > a real bug in Git affecting other platforms as well, but these tests > > > are too lax to catch it. > > I am seeing this very frequently now, as it feels like failing in the > Azure Pipeline about half of the time. I was wondering whether it's only an issue on Travis CI, and was waiting whether you'll complain about it :) Evidently it is not, but I still would like to see a report about macOS running directly on someone's Mac hardware, i.e. without all the CI/cloud/whatnot magic. > Any ideas how to fix this test, anyone? I'm afraid that this is not merely an issue with the test, but a platform issue that we should work around somehow. I would have suggested to follow up on what Peff suggested, but I see that you already did, and it didn't work out... In the meantime, for lack of a better option, I started to skip the two failure-prone tests in the OSX build jobs in my automated CI builds with: -- >8 -- Subject: [PATCH] travis-ci: skip flaky tests in 't5570-git-daemon.sh' in OSX build jobs See: https://public-inbox.org/git/CAM0VKj=MCS+cmOgzf_XyPeb+qZrFmuMH52-PV_NDMZA9X+rRoA@xxxxxxxxxxxxxx/ Signed-off-by: SZEDER Gábor <szeder.dev@xxxxxxxxx> --- ci/lib-travisci.sh | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/ci/lib-travisci.sh b/ci/lib-travisci.sh index 69dff4d1ec..1cd2c1db7d 100755 --- a/ci/lib-travisci.sh +++ b/ci/lib-travisci.sh @@ -121,7 +121,9 @@ osx-clang|osx-gcc) # t9810 occasionally fails on Travis CI OS X # t9816 occasionally fails with "TAP out of sequence errors" on # Travis CI OS X - export GIT_SKIP_TESTS="t9810 t9816" + # In 't5570-git-daemon.sh', the tests 'fetch notices corrupt pack' + # and 'fetch notices corrupt idx' fail rather frequently. + export GIT_SKIP_TESTS="t9810 t9816 t5570.9 t5570.10" ;; GIT_TEST_GETTEXT_POISON) export GIT_TEST_GETTEXT_POISON=YesPlease -- 2.20.1.940.g8404bb2d1a -- >8 -- > > > What it boils down to is this sequence: > > > > > > - The test first prepares a repository containing a corrupt pack, > > > ready to be server via 'git daemon'. > > > > > > - Then the test runs 'test_must_fail git fetch ....', which connects > > > to 'git daemon', which forks 'git upload-pack', which then > > > advertises refs (only HEAD) and capabilities. So far so good. > > > > > > - 'git fetch' eventually calls fetch-pack.c:find_common(). The > > > first half of this function assembles a request consisting of a > > > want and a flush pkt-line, and sends it via a send_request() call. > > > > > > At this point the scheduling becomes important: let's suppose that > > > fetch is slow and upload-pack is fast. > > > > > > - 'git upload-pack' receives the request, parses the want line, > > > notices the corrupt pack, responds with an 'ERR upload-pack: not > > > our ref' pkt-line, and die()s right away. > > > > > > - 'git fetch' finally approaches the end of the function, where it > > > attempts to send a done pkt-line via another send_request() call > > > through the now closing TCP socket. > > > > > > - What happens now seems to depend on the platform: > > > > > > - On Linux, both on my machine and on Travis CI, it shows textbook > > > example behaviour: write() returns with error and sets errno to > > > ECONNRESET. Since it happens in write_or_die(), 'git fetch' > > > die()s with 'fatal: write error: Connection reset by peer', and > > > doesn't show the error send by 'git upload-pack'; how could it, > > > it doesn't even get as far to receive upload-pack's ERR > > > pkt-line. > > > > > > The test only checks that 'git fetch' fails, but it doesn't > > > check whether it failed with the right error message, so the > > > test still succeeds. Had it checked the error message as well, > > > we most likely had noticed this issue already, it doesn't happen > > > all that rarely. > > > > > > - On the new OSX images with XCode 9.4 on Travis CI the write() > > > triggers SIGPIPE right away, and 'test_must_fail' notices it and > > > fails the test. I couldn't see any sign of an ECONNRESET or any > > > other error that we could act upon to avoid the SIGPIPE. > > > > > > - On OSX with XCode 9.2 on Travis CI there is neither SIGPIPE, nor > > > ECONNRESET, but sending the request actually succeeds even > > > though there is no process on the other end of the socket > > > anymore. 'git fetch' then simply continues execution, reads and > > > parses the ERR pkt-line, and then dies()s with 'fatal: remote > > > error: upload-pack: not our ref'. So, on the face of it, it > > > shows the desired behaviour, but I have no idea how that write() > > > could succeed instead of returning error. > > > > > > I don't know what happens on a real Mac as I don't have access to one; > > > I figured out all the above by enabling packet tracing, adding a > > > couple of well placed tracing printf() and sleep() calls, running a > > > bunch of builds on Travis CI, and looking through their logs. But > > > without access to a debugger and netstat and what not I can't really > > > go any further. So I would now happily pass the baton to those who > > > have a Mac and know a thing or two about its porting issues to first > > > check whether OSX on a real Mac shows the same behaviour as it does in > > > Travis CI's virtualized(?) environment. And then they can pass the > > > baton to those who know all the intricacies of the pack protocol and > > > its implementation to decide what to do with this issue. > > > > > > For a mostly reliable reproduction recipe you might want to fetch this > > > branch: > > > > > > https://github.com/szeder/git t5570-git-daemon-sigpipe > > > > > > and then run 'make && cd t && ./t5570-git-daemon.sh -v -x' > > > > > > > > > Have fun! ;) > > > > > > > > > 1 - https://blog.travis-ci.com/2018-07-19-xcode9-4-default-announce > > > > > > 2 - On git.git's master: > > > https://travis-ci.org/git/git/jobs/411517552#L2717 > > > >
