gcc9.1 and f2fs

[Neil MacLeod]

With the latest grub HEAD (620857c4dccb8f0548cdb855f6b2f46ebea3919e)
I'm getting the following compilation error with gcc-9.1:

/home/ubuntu/projects/LibreELEC.tv/build.LibreELEC-Generic.x86_64-9.1-devel/toolchain/bin/x86_64-libreelec-linux-gnu-gcc
-DHAVE_CONFIG_H -I.  -Wall -W -DGRUB_UTIL=1 -D_FILE_OFFSET_BITS=64
-I./include -DGRUB_FILE=\"grub-core/fs/xfs.c\" -I. -I. -I. -I.
-I./include -I./include -I./grub-core/lib/libgcrypt-grub/src/
-I./grub-core/lib/minilzo -I./grub-core/lib/xzembed
-I./grub-core/lib/zstd -DMINILZO_HAVE_CONFIG_H -D_FILE_OFFSET_BITS=64
-fno-builtin-gettext -Wall -W -Wshadow -Wpointer-arith -Wundef
-Wchar-subscripts -Wcomment -Wdeprecated-declarations
-Wdisabled-optimization -Wdiv-by-zero -Wfloat-equal
-Wformat-extra-args -Wformat-security -Wformat-y2k -Wimplicit
-Wimplicit-function-declaration -Wimplicit-int -Wmain -Wmissing-braces
-Wmissing-format-attribute -Wmultichar -Wparentheses -Wreturn-type
-Wsequence-point -Wshadow -Wsign-compare -Wswitch -Wtrigraphs
-Wunknown-pragmas -Wunused -Wunused-function -Wunused-label
-Wunused-parameter -Wunused-value  -Wunused-variable -Wwrite-strings
-Wnested-externs -Wstrict-prototypes -Wcast-align  -Wextra
-Wattributes -Wendif-labels -Winit-self -Wint-to-pointer-cast
-Winvalid-pch -Wmissing-field-initializers -Wnonnull -Woverflow -Wvla
-Wpointer-to-int-cast -Wstrict-aliasing -Wvariadic-macros
-Wvolatile-register-var -Wpointer-sign -Wmissing-include-dirs
-Wmissing-prototypes -Wmissing-declarations -Wformat=2 -Werror
-fno-builtin -Wno-undef
-I/home/ubuntu/projects/LibreELEC.tv/build.LibreELEC-Generic.x86_64-9.1-devel/toolchain/x86_64-libreelec-linux-gnu/sysroot/usr/include
-fomit-frame-pointer -D_FILE_OFFSET_BITS=64 -MT
grub-core/fs/libgrubmods_a-xfs.o -MD -MP -MF
grub-core/fs/.deps-util/libgrubmods_a-xfs.Tpo -c -o
grub-core/fs/libgrubmods_a-xfs.o `test -f 'grub-core/fs/xfs.c' || echo
'./'`grub-core/fs/xfs.c
grub-core/fs/f2fs.c: In function 'grub_f2fs_label':
grub-core/fs/f2fs.c:1248:60: error: taking address of packed member of
'struct grub_f2fs_superblock' may result in an unaligned pointer value
[-Werror=address-of-packed-member]
 1248 |     *label = (char *) grub_f2fs_utf16_to_utf8
(data->sblock.volume_name);
      |                                                ~~~~~~~~~~~~^~~~~~~~~~~~
cc1: all warnings being treated as errors
make[3]: *** [Makefile:6943: grub-core/fs/libgrubmods_a-f2fs.o] Error 1
make[3]: *** Waiting for unfinished jobs....

Does anyone have a patch?

Full build log: http://ix.io/1Iet

Many thanks!
Neil