On Wed, Dec 20, 2023 at 4:41 AM Dominique Devienne <ddevienne@xxxxxxxxx> wrote: > On Tue, Dec 19, 2023 at 2:02 PM Thomas Munro <thomas.munro@xxxxxxxxx> wrote: >> On Wed, Dec 20, 2023 at 1:39 AM Dominique Devienne <ddevienne@xxxxxxxxx> wrote: >> > Program received signal SIGSEGV, Segmentation fault. >> > 0x00000000004232b8 in slash_yylex () >> >> I think this might have to do with flex changing. Does it help if you >> "make maintainer-clean"? > > My colleague who did the custom build double-checked the flex/bison requirements, > and the version of the packages on the RH7 machine he built on, and they check out (see below). > > He also tells me he builds debug and release versions off different workspaces/checkouts, > thus there are no remnants of previous builds, assuming that's what `make maintainer-clean` is for. OK but be warned that if you're using tarballs, we shipped lexer remnants in the tree (until https://github.com/postgres/postgres/commit/721856ff, an interesting commit to read). The slash lexer is a kind of extension that (IIRC) shares the same PsqlScanState (opaque pointer to private lexer state), but if these two things are compiled to C by different flex versions, they may contain non-identical 'struct yyguts_t' (and even if the structs were identical, what the code does with them might still be incompatible, but I guess the struct itself would be a good first thing to look at along with the versions mentioned near the top of the .c): src/fe_utils/psqlscan.l -> psqlscan.c src/bin/psql/psqlscanslash.l -> psqlscanslash.c The usual "clean" doesn't remove those .c files in PG < 17, which means that if your pipeline involves tarballs but you finished up regenerating one of the files, or some other sequence involving different flex versions, you could get that. I've seen it myself on a few systems, a decade ago when I guess flex rolled out an incompatible change (maybe contemporaneous with RHEL7) and flex was upgraded underneath my feet. I remember that "maintainer-clean" (or maybe I'm misremembering and it was "distclean") fixed it.
