https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84919
--- Comment #29 from Marietto <marietto2008 at gmail dot com> --- I get this error : gcc -m64 -DBUILD_ID -fno-strict-aliasing -std=gnu99 -Wall -Wstrict-prototypes -Wdeclaration-after-statement -Wno-unused-but-set-variable -Wno-unused-local-typedefs -O2 -fomit-frame-pointer -nostdinc -fno-builtin -fno-common -Werror -Wredundant-decls -Wno-pointer-arith -pipe -g -D__XEN__ -include /etc/xen/igvtg-xen/xen/include/xen/config.h '-D__OBJECT_FILE__="trace.o"' -Wa,--strip-local-absolute -MMD -MF ./.trace.o.d -I/etc/xen/igvtg-xen/xen/include -I/etc/xen/igvtg-xen/xen/include/asm-x86/mach-generic -I/etc/xen/igvtg-xen/xen/include/asm-x86/mach-default -DXEN_IMG_OFFSET=0x200000 '-D__OBJECT_LABEL__=common$trace.o' -msoft-float -fno-stack-protector -fno-exceptions -Wnested-externs -DHAVE_GAS_VMX -DHAVE_GAS_SSE4_2 -DHAVE_GAS_EPT -DHAVE_GAS_RDRAND -DHAVE_GAS_FSGSBASE -DHAVE_GAS_RDSEED -U__OBJECT_LABEL__ -DHAVE_GAS_QUOTED_SYM '-D__OBJECT_LABEL__=common/trace.o' -mno-red-zone -mno-sse -fpic -fno-asynchronous-unwind-tables -DGCC_HAS_VISIBILITY_ATTRIBUTE -c trace.c -o trace.o trace.c: In function ‘__trace_hypercall’: trace.c:829:19: error: taking address of packed member of ‘struct ’ may result in an unaligned pointer value [-Werror=address-of-packed-member] 829 | uint32_t *a = d.args; | ^ cc1: all warnings being treated as errors
