On Sat, Oct 26, 2019 at 10:56:45PM +0200, Johannes Schindelin wrote: > Back to the issue at hand: I did open a GitGitGadget PR with my proposed > change, in the hopes that I could somehow fast-track this fix into the > CI/PR builds over at https://github.com/gitgitgadget/git, but there are > problems: it seems that now there is an at least occasional broken pipe > in the same test when run on macOS. Yes, I think that's another issue in the same test. There's more discussion further down in the thread I linked earlier, starting here: https://public-inbox.org/git/20190829143805.GB1746@xxxxxxxxxxxxxxxxxxxxx/ and I think Gábor's solution here: https://public-inbox.org/git/20190830121005.GI8571@xxxxxxxxxx/ is the right direction (and note that this _isn't_ just a test artifact, but a bug that occasionally hits real-world cases, too). > There _also_ seems to be something spooky going on in t3510.12 and .13, > where the expected output differs from the actual output only by a > re-ordering of the lines: > > -- snip -- > [...] > +++ diff -u expect advice > --- expect 2019-10-25 22:17:44.982884700 +0000 > +++ advice 2019-10-25 22:17:45.278884500 +0000 > @@ -1,3 +1,3 @@ > error: cherry-pick is already in progress > -hint: try "git cherry-pick (--continue | --skip | --abort | --quit)" > fatal: cherry-pick failed > +hint: try "git cherry-pick (--continue | --skip | --abort | --quit)" > -- snap -- Hrm. I'd have thought those are both coming from the same process. Which implies that we're not fflushing stderr before calling write(2). But your patch seems to do so... <scratches head> Aha. I think you force-pushed up as I am typing this. :) So I think that is indeed the solution. > So much as I would love to see the flakiness of t5516 be fixed as soon > as possible, I fear we will have to look at the underlying issue a bit > closer: there are two processes writing to `stderr` concurrently. I > don't know whether there would be a good way for the `stderr` of the > `upload-pack` process to be consumed by the `fetch` process, and to be > printed by the latter. The worst part is that this message already _is_ consumed by fetch: we send it twice, once over the sideband, and once directly to stderr. In most cases the stderr version is lost, but some server providers might be collecting it. I wouldn't mind seeing the direct-to-stderr one dropped. There's some more discussion in (from the same thread linked earlier): https://public-inbox.org/git/20190828145412.GB14432@xxxxxxxxxxxxxxxxxxxxx/ -Peff
