Hi,

gcc-riscv64-unknown-elf fails to build in a test rebuild on at least amd64 and arm64 with
gcc-16/g++-16, but builds properly with gcc-15/g++-15. The severity of this
report will be raised before the forky release.

The full build log can be found at:
https://people.debian.org/~ema/gcc-16-rebuilds/output-1/gcc-riscv64-unknown-elf_arm64.build.xz

The last lines of the build log are at the end of this report.

To build with GCC 16, either set CC=gcc-16 CXX=g++-16 explicitly,
or install the gcc, g++, gfortran, ... packages from experimental.

  apt-get -t=experimental install g++

Common build failures include unused (but set) variables, array subscripts
partly outside array bounds, and new/dropped symbols in Debian symbols files.
For other C/C++ related build failures see the porting guide at
http://gcc.gnu.org/gcc-16/porting_to.html

Please only close this issue after double-checking that the package can be
built correctly with GCC 16.

Please do not reassign this bug to another package. If a fix in another package
is required, then file a bug for the other package (or clone), and mark this
bug as blocked by the bug in the other package.

[...]


checking for sbrk... checking whether asprintf is declared... yes
yes
checking whether basename is declared... checking whether vasprintf is declared... yes
checking whether ffs is declared... yes
checking whether snprintf is declared... yes
checking whether asprintf is declared... yes
checking whether vsnprintf is declared... yes
checking whether vasprintf is declared... yes
checking whether calloc is declared... yes
checking whether snprintf is declared... yes
checking whether getenv is declared... yes
checking whether vsnprintf is declared... yes
checking whether getopt is declared... yes
checking whether calloc is declared... yes
yes
checking whether malloc is declared... checking whether getenv is declared... yes
yes
checking whether getopt is declared... checking whether realloc is declared... yes
yes
checking whether malloc is declared... checking whether sbrk is declared... yes
yes
checking whether strtol is declared... checking whether realloc is declared... yes
yes
checking whether strtoul is declared... checking whether sbrk is declared... yes
checking whether strtoll is declared... yes
checking whether strtol is declared... yes
yes
checking whether strtoul is declared... checking whether strtoull is declared... yes
yes
checking whether strtoll is declared... checking whether strverscmp is declared... yes
yes
checking whether strtoull is declared... checking whether strnlen is declared... yes
yes
checking whether canonicalize_file_name must be declared... checking whether strverscmp is declared... no
checking for SHA1 HW acceleration support... yes
checking whether strnlen is declared... no
checking for stdlib.h... (cached) yes
checking for unistd.h... (cached) yes
checking for sys/param.h... (cached) yes
checking for getpagesize... (cached) yes
checking for working mmap... yes
checking whether canonicalize_file_name must be declared... no
checking for SHA1 HW acceleration support... yes
checking for working strncmp... no
checking for stdlib.h... (cached) yes
checking for unistd.h... (cached) yes
checking for sys/param.h... (cached) yes
checking for getpagesize... (cached) yes
checking for working mmap... yes
configure: updating cache ./config.cache
configure: creating ./config.status
yes
checking for working strncmp... config.status: creating Makefile
config.status: creating testsuite/Makefile
config.status: creating config.h
config.status: executing default commands
yes
configure: updating cache ./config.cache
configure: creating ./config.status
config.status: creating Makefile
config.status: creating testsuite/Makefile
config.status: creating config.h
config.status: executing default commands
make[3]: Leaving directory '/build/reproducible-path/gcc-riscv64-unknown-elf-23/build-riscv64-unknown-elf'
make[2]: *** [Makefile:1041: all] Error 2
make[2]: Leaving directory '/build/reproducible-path/gcc-riscv64-unknown-elf-23/build-riscv64-unknown-elf'
dh_auto_build: error: cd build-riscv64-unknown-elf && make -j128 -j100 returned exit code 2
make[1]: *** [debian/rules:123: override_dh_auto_build] Error 25
make[1]: Leaving directory '/build/reproducible-path/gcc-riscv64-unknown-elf-23'
make: *** [debian/rules:100: binary] Error 2
dpkg-buildpackage: error: debian/rules binary subprocess failed with exit status 2