On Thu, Sep 24, 2026 at 05:17:28PM +0100, Collin Funk wrote: > Pádraig Brady <[email protected]> writes: > > > On 24/09/2026 22:18, Paul Eggert wrote: > >> On 2026-09-24 07:52, Collin Funk wrote: > >>> It has been a while since I looked at pipe-f2.sh, but I remember coming > >>> to the conclusion that it was a NetBSD bug [1] > >>> [1]https://lists.gnu.org/archive/html/coreutils/2026-04/msg00129.html > >> There do seem to be problems in that area. See NetBSD PR kern/57659 > >> <https://gnats.netbsd.org/57659>, along with test cases added yesterday > >> (!) trying to catch a similar bug with fifos and ptys, e.g., > >> <https://github.com/NetBSD/src/commit/abad86f745946a5718e2b9c6559c7513f56edc01>. > > > > Interesting. I also see the following which seems like it might be related: > > https://github.com/NetBSD/src/commit/b736ec86d > > > > I've not looked at those in detail, > > but I suspect that may have regressed against the POSIX > > requirement for fifos, that... > > > > “If no process has the pipe open for writing, read() shall return 0 to > > indicate end-of-file.” > > > > I.e. the subsequent blocking after the first read() returning EOF should > > not happen. > > Yes, that was the conclusion that I came to a few months ago it seems > [1]. > > Collin > > [1] https://lists.gnu.org/archive/html/coreutils/2026-04/msg00129.html
Sorry, I'm confused by the timing here. Do you (Pádraig) think the patch in https://github.com/NetBSD/src/commit/b736ec86d is a POSIX regression? Or do you (Collin) think it fixes the problem you saw months ago? (The patch is three days old, and I'm not running it on my machine yet.) Thomas
