Unable to build an empty module.

[MasterCATZ]

I have not been able to get zfs to build since 5.11 as far as I know the kernel was built with configurable modules ?
Ubuntu 20.04

aio@aio:/SnapRaidArray/DATA/git/zfs$ ./autogen.sh
autoreconf: Entering directory .' autoreconf: configure.ac: not using Gettext autoreconf: running: aclocal --force -I config autoreconf: configure.ac: tracing autoreconf: configure.ac: AM_GNU_GETTEXT is used, but not AM_GNU_GETTEXT_VERSION autoreconf: running: libtoolize --copy --force libtoolize: putting auxiliary files in AC_CONFIG_AUX_DIR, 'config'. libtoolize: copying file 'config/ltmain.sh' libtoolize: putting macros in AC_CONFIG_MACRO_DIRS, 'config'. libtoolize: copying file 'config/libtool.m4' libtoolize: copying file 'config/ltoptions.m4' libtoolize: copying file 'config/ltsugar.m4' libtoolize: copying file 'config/ltversion.m4' libtoolize: copying file 'config/lt~obsolete.m4' autoreconf: running: /usr/bin/autoconf --force autoreconf: running: /usr/bin/autoheader --force autoreconf: running: automake --add-missing --copy --force-missing configure.ac:48: installing 'config/compile' configure.ac:42: installing 'config/missing' cmd/mount_zfs/Makefile.am: installing 'config/depcomp' autoreconf: Leaving directory .'

aio@aio:/SnapRaidArray/DATA/git/zfs$ ./configure
checking for gawk... gawk
checking metadata... git describe
checking build system type... x86_64-pc-linux-gnu
checking host system type... x86_64-pc-linux-gnu
checking target system type... x86_64-pc-linux-gnu
checking whether to enable maintainer-specific portions of Makefiles... no
checking whether make supports nested variables... yes
checking for a BSD-compatible install... /usr/bin/install -c
checking whether build environment is sane... yes
checking for a thread-safe mkdir -p... /usr/bin/mkdir -p
checking whether make sets $(MAKE)... yes
checking how to print strings... printf
checking whether make supports the include directive... yes (GNU style)
checking for gcc... gcc
checking whether the C compiler works... yes
checking for C compiler default output file name... a.out
checking for suffix of executables...
checking whether we are cross compiling... no
checking for suffix of object files... o
checking whether we are using the GNU C compiler... yes
checking whether gcc accepts -g... yes
checking for gcc option to accept ISO C89... none needed
checking whether gcc understands -c and -o together... yes
checking dependency style of gcc... gcc3
checking for a sed that does not truncate output... /usr/bin/sed
checking for grep that handles long lines and -e... /usr/bin/grep
checking for egrep... /usr/bin/grep -E
checking for fgrep... /usr/bin/grep -F
checking for ld used by gcc... /usr/bin/ld
checking if the linker (/usr/bin/ld) is GNU ld... yes
checking for BSD- or MS-compatible name lister (nm)... /usr/bin/nm -B
checking the name lister (/usr/bin/nm -B) interface... BSD nm
checking whether ln -s works... yes
checking the maximum length of command line arguments... 1572864
checking how to convert x86_64-pc-linux-gnu file names to x86_64-pc-linux-gnu format... func_convert_file_noop
checking how to convert x86_64-pc-linux-gnu file names to toolchain format... func_convert_file_noop
checking for /usr/bin/ld option to reload object files... -r
checking for objdump... objdump
checking how to recognize dependent libraries... pass_all
checking for dlltool... no
checking how to associate runtime and link libraries... printf %s\n
checking for ar... ar
checking for archiver @file support... @
checking for strip... strip
checking for ranlib... ranlib
checking command to parse /usr/bin/nm -B output from gcc object... ok
checking for sysroot... no
checking for a working dd... /usr/bin/dd
checking how to truncate binary pipes... /usr/bin/dd bs=4096 count=1
checking for mt... mt
checking if mt is a manifest tool... no
checking how to run the C preprocessor... gcc -E
checking for ANSI C header files... yes
checking for sys/types.h... yes
checking for sys/stat.h... yes
checking for stdlib.h... yes
checking for string.h... yes
checking for memory.h... yes
checking for strings.h... yes
checking for inttypes.h... yes
checking for stdint.h... yes
checking for unistd.h... yes
checking for dlfcn.h... yes
checking for objdir... .libs
checking if gcc supports -fno-rtti -fno-exceptions... no
checking for gcc option to produce PIC... -fPIC -DPIC
checking if gcc PIC flag -fPIC -DPIC works... yes
checking if gcc static flag -static works... yes
checking if gcc supports -c -o file.o... yes
checking if gcc supports -c -o file.o... (cached) yes
checking whether the gcc linker (/usr/bin/ld -m elf_x86_64) supports shared libraries... yes
checking whether -lc should be explicitly linked in... no
checking dynamic linker characteristics... GNU/Linux ld.so
checking how to hardcode library paths into programs... immediate
checking whether stripping libraries is possible... yes
checking if libtool supports shared libraries... yes
checking whether to build shared libraries... yes
checking whether to build static libraries... yes
checking for gcc... (cached) gcc
checking whether we are using the GNU C compiler... (cached) yes
checking whether gcc accepts -g... (cached) yes
checking for gcc option to accept ISO C89... (cached) none needed
checking whether gcc understands -c and -o together... (cached) yes
checking dependency style of gcc... (cached) gcc3
checking whether ln -s works... yes
checking for pkg-config... /usr/bin/pkg-config
checking pkg-config is at least version 0.9.0... yes
checking dependency style of gcc... gcc3
checking whether to build with code coverage support... no
checking how to create a pax tar archive... gnutar
checking zfs author... OpenZFS
checking zfs license... CDDL
checking whether NLS is requested... yes
checking for msgfmt... /usr/bin/msgfmt
checking for gmsgfmt... /usr/bin/msgfmt
checking for xgettext... /usr/bin/xgettext
checking for msgmerge... /usr/bin/msgmerge
checking for ld... /usr/bin/ld -m elf_x86_64
checking if the linker (/usr/bin/ld -m elf_x86_64) is GNU ld... yes
checking for shared library run path origin... done
checking 32-bit host C ABI... no
checking for the common suffixes of directories in the library search path... lib,lib
checking zfs config... all
checking the number of available CPUs... 24
checking whether gcc supports -Wno-unused-but-set-variable... yes
checking whether gcc supports -Wno-bool-compare... yes
checking whether gcc supports -Wframe-larger-than=... yes
checking whether gcc supports -Wno-format-truncation... yes
checking whether gcc supports -Wno-format-zero-length... yes
checking whether gcc supports -fno-omit-frame-pointer... yes
checking whether gcc supports -fno-ipa-sra... yes
checking whether to build with -fsanitize=address support... no
checking whether host toolchain supports SSE... yes
checking whether host toolchain supports SSE2... yes
checking whether host toolchain supports SSE3... yes
checking whether host toolchain supports SSSE3... yes
checking whether host toolchain supports SSE4.1... yes
checking whether host toolchain supports SSE4.2... yes
checking whether host toolchain supports AVX... yes
checking whether host toolchain supports AVX2... yes
checking whether host toolchain supports AVX512F... yes
checking whether host toolchain supports AVX512CD... yes
checking whether host toolchain supports AVX512DQ... yes
checking whether host toolchain supports AVX512BW... yes
checking whether host toolchain supports AVX512IFMA... yes
checking whether host toolchain supports AVX512VBMI... yes
checking whether host toolchain supports AVX512PF... yes
checking whether host toolchain supports AVX512ER... yes
checking whether host toolchain supports AVX512VL... yes
checking whether host toolchain supports AES... yes
checking whether host toolchain supports PCLMULQDQ... yes
checking whether host toolchain supports MOVBE... yes
checking for system type (linux-gnu)... Linux
checking for python3... python3
checking for python version... 3.8
checking for python platform... linux
checking for python script directory... ${prefix}/lib/python3.8/site-packages
checking for python extension module directory... ${exec_prefix}/lib/python3.8/site-packages
checking for python3 module: packaging... yes
checking for python3.8... /usr/bin/python3.8
checking for a version of Python >= '2.1.0'... yes
checking for a version of Python >= '3.4.0'... yes
checking for the distutils Python package... yes
checking for Python include path... -I/usr/include/python3.8
checking for Python library path... -L/usr/lib -lpython3.8
checking for Python site-packages path... /usr/lib/python3/dist-packages
checking python extra libraries... -lcrypt -lpthread -ldl -lutil -lm -lm
checking python extra linking flags... -Xlinker -export-dynamic -Wl,-O1 -Wl,-Bsymbolic-functions
checking consistency of all components of python development environment... yes
checking for python3.8 module: setuptools... yes
checking for python3.8 module: cffi... yes
checking whether to enable pyzfs: ... yes
checking for sed --in-place... --in-place
checking for cppcheck... no
checking for shellcheck... no
checking for checkbashisms... yes
checking for CFPreferencesCopyAppValue... no
checking for CFLocaleCopyCurrent... no
checking for CFLocaleCopyPreferredLanguages... no
checking for GNU gettext in libc... yes
checking whether to use NLS... yes
checking where the gettext function comes from... libc
checking for dracut directory... /usr/share/dracut
checking for zlib... yes
checking for zlib.h... yes
checking for compress2 in -lz... yes
checking for uncompress in -lz... yes
checking for crc32 in -lz... yes
checking for udev directories... /lib/udev;/lib/udev/rules.d
checking for systemd support... yes
checking for uuid... yes
checking for uuid/uuid.h... yes
checking for uuid_generate in -luuid... yes
checking for uuid_is_null in -luuid... yes
checking for blkid... yes
checking for blkid/blkid.h... yes
checking for main in -lblkid... yes
checking for library containing xdrmem_create... none required
checking for libudev... yes
checking for libudev.h... yes
checking for main in -ludev... yes
checking for udev_device_get_is_initialized... yes
checking for libcrypto... yes
checking for openssl/evp.h... yes
checking for PKCS5_PBKDF2_HMAC_SHA1 in -lcrypto... yes
checking for libaio.h... yes
checking for main in -laio... yes
checking whether -latomic is required... no
checking for libfetch... libcurl
checking for clock_gettime... yes
checking security/pam_modules.h usability... yes
checking security/pam_modules.h presence... yes
checking for security/pam_modules.h... yes
checking makedev() is declared in sys/sysmacros.h... yes
checking makedev() is declared in sys/mkdev.h... no
checking for issetugid... no
checking for mlockall... yes
checking for strlcat... no
checking for strlcpy... no
checking kernel source directory... /usr/src/linux-headers-5.13.9-051309-generic
checking kernel build directory... /usr/src/linux-headers-5.13.9-051309-generic
checking kernel source version... 5.13.9-051309-generic
checking kernel file name for module symbols... Module.symvers
checking whether modules can be built... no
configure: error:
*** Unable to build an empty module.

aio@aio:/SnapRaidArray/DATA/git/zfs$ grep CONFIG_MODULES /boot/config-5.
config-5.10.26-051026-generic config-5.13.9-051309-generic
config-5.11.10-051110-generic config-5.4.0-42-generic
config-5.11.20-051120-generic config-5.4.0-77-generic
config-5.12.0-051200-generic config-5.4.0-80-generic
config-5.13.0-051300-generic
aio@aio:/SnapRaidArray/DATA/git/zfs$ grep CONFIG_MODULES /boot/config-5.13.
config-5.13.0-051300-generic config-5.13.9-051309-generic
aio@aio:/SnapRaidArray/DATA/git/zfs$ grep CONFIG_MODULES /boot/config-5.13.0-051300-generic
CONFIG_MODULES_USE_ELF_RELA=y
CONFIG_MODULES=y
CONFIG_MODULES_TREE_LOOKUP=y

[MasterCATZ]

Kernel 5.11.10 was the last version I was able to build then this error started popping up

[rnickle]

When I build (5.13.12) I unpack the Linux source, then go there and:

# cd $LINUX_SRC
# make olddefconfig
# make prepare
# make

Then specify an explicit kernel source directory in my ./configure:

```bash
# cd $ZFS_SRC
# ./configure --prefix=/ --libdir=/lib --includedir=/usr/include --datarootdir=/usr/share --with-linux="$LINUX_SRC" --with-linux-obj="$LINUX_SRC"

[MasterCATZ]

so not possible without making your own kernel ? can not use the kernels auto updated from ubuntu ?

[behlendorf]

PR #12525 may resolve your issue. It hasn't yet been merged to a release so you'll need to cherry pick it for now.