Compiling from Mar2018 branch, today's hg tip, with production settings: --disable-debug --disable-developer --disable-assert --enable-optimize Fails with this on Fedora 28: In file included from /usr/include/string.h:494, from /home/roberto/MonetDBServer/MonetDB.Spinque_Mar2018/src/gdk/gdk.h:316, from /home/roberto/MonetDBServer/MonetDB.Spinque_Mar2018/src/gdk/gdk_calc.c:10: In function ‘memcpy’, inlined from ‘addstr_loop’ at /home/roberto/MonetDBServer/MonetDB.Spinque_Mar2018/src/gdk/gdk_calc.c:3415:3: /usr/include/bits/string_fortified.h:34:10: error: ‘__builtin_memcpy’ forming offset [3, 65535] is out of the bounds [0, 2] of object ‘str_nil’ with type ‘const char[2]’ [-Werror=array-bounds] return __builtin___memcpy_chk (__dest, __src, __len, __bos0 (__dest)); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ (same error in several files) Compiling with debug settings succeeds: --enable-debug --enable-developer --enable-assert --disable-optimize Is this reproducible or has it something to do with my machine?