ARCH_FLAGS was always present and is documented as being fed to both
CC and LD during the build. This is meant for options that need to be
consistent between the two stages such as -pg, -flto, -fsanitize=address,
-m64, -g etc. Its doc was lacking a bit of clarity though, and it was
not enumerated in the makefile's variables list.
ARCH however was only documented as affecting ARCH_FLAGS, and was just
never used as the only two really usable and supported ARCH_FLAGS options
were -m32 and -m64. In addition it was even written in the makefile that
it was CPU that was affecting the ARCH_FLAGS. Let's just drop ARCH and
improve the documentation on ARCH_FLAGS. Again, if ARCH is set, a warning
is emitted explaining how to proceed.
ARCH_FLAGS is now preset to -g so that we finally have a correct place
to deal with such debugging options that need to be passed to both
stages. The fedora and musl CI workflows were updated to also use it
instead of sticking to duplicate DEBUG_CFLAGS+LDFLAGS.
It's also worth noting that BUILD_ARCH was being passed to the build
process and never used anywhere in the code, so its removal will not
be noticed.
This patch allows to show the backtrace of a coredump produced in the
alpine/musl jobs.
It activates some option required by the containers to allow the
production of coredump, set a shared directory so the kernel could dump
the coredump within the container. Some debug packages were also added.