Hi, On Thu, Jan 10, 2019 at 02:14:14AM +0500, Andrey Rahmatullin wrote: > On Wed, Jan 09, 2019 at 09:42:43PM +0100, Andreas Tille wrote: > > to find the exact code line where the SIGSEGV is thrown. It turns out > > that the elements of a structure are not accessible: > > > > (gdb) print entry->offset > > Cannot access memory at address 0x7 > It's because entry is 0x7.
When I was running the code with some more debugging info activated I had pretty valid looking adresses 0x555666 (or something in that line just remembering by heart - can activate the patch if needed). I have no idea why the address is this without that extra debug code. > > The values of the structure are set in line 350 and are OK there. > The problem is not about the structure fields but about the structure > pointer itself though. > ... > You need to find out why one of the tree nodes has an invalid address. Can you propose any means to find this out? I have no idea about specific compiler differences. BTW, I also tried to set -O0 but this did not avoided the SIGSEGV. Thanks for your hint anyway Andreas.  https://salsa.debian.org/med-team/ffindex/blob/master/debian/patches/debug_segfault -- http://fam-tille.de