Hi,

octave-parallel 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/octave-parallel_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.

[...]


custom.h:11:10: fatal error: octave/toplev.h: No such file or directory
   11 | #include <octave/toplev.h>
      |          ^~~~~~~~~~~~~~~~~
compilation terminated.
In file included from config.h:1340,
                 from select.cc:18:
custom.h:11:10: fatal error: octave/toplev.h: No such file or directory
   11 | #include <octave/toplev.h>
      |          ^~~~~~~~~~~~~~~~~
compilation terminated.
In file included from config.h:1340,
                 from parallel-gnutls.h:27,
                 from <stdin>:24:
custom.h:11:10: fatal error: octave/toplev.h: No such file or directory
   11 | #include <octave/toplev.h>
      |          ^~~~~~~~~~~~~~~~~
compilation terminated.
make[1]: *** [Makefile:202: select.o] Error 1
make[1]: *** [Makefile:199: select_sockets.o] Error 1
In file included from config.h:1340,
                 from parallel-gnutls.h:27,
                 from make-cmd-string.cc:26:
custom.h:11:10: fatal error: octave/toplev.h: No such file or directory
   11 | #include <octave/toplev.h>
      |          ^~~~~~~~~~~~~~~~~
compilation terminated.
make[1]: *** [Makefile:205: make-cmd-string.o] Error 1
In file included from config.h:1340,
                 from parallel-gnutls.h:27,
                 from parcellfun_set_nproc.cc:24:
custom.h:11:10: fatal error: octave/toplev.h: No such file or directory
   11 | #include <octave/toplev.h>
      |          ^~~~~~~~~~~~~~~~~
compilation terminated.
make[1]: *** [Makefile:205: parcellfun_set_nproc.o] Error 1
In file included from config.h:1340,
                 from parallel-gnutls.h:27,
                 from gnutls-callbacks.cc:20:
custom.h:11:10: fatal error: octave/toplev.h: No such file or directory
   11 | #include <octave/toplev.h>
      |          ^~~~~~~~~~~~~~~~~
compilation terminated.
make[1]: *** [Makefile:199: gnutls-callbacks.o] Error 1
rm -f libgnu.a
ar cr libgnu.a c-ctype.o cloexec.o dirname-lgpl.o basename-lgpl.o stripslash.o fd-hook.o glthread/lock.o malloca.o nproc.o sig-handler.o sockets.o stat-time.o sys_socket.o glthread/threadlib.o unistd.o xsize.o asnprintf.o fcntl.o printf-args.o printf-parse.o strerror_r.o vasnprintf.o
ranlib libgnu.a
make[4]: Leaving directory '/tmp/oct-GUHvFv/octave-parallel-4.0.2/src/gl'
make[3]: Leaving directory '/tmp/oct-GUHvFv/octave-parallel-4.0.2/src/gl'
make[2]: Leaving directory '/tmp/oct-GUHvFv/octave-parallel-4.0.2/src/gl'
octave-pserver.cc: In function ‘int main(int, char**)’:
octave-pserver.cc:385:10: warning: ‘void* __builtin___memcpy_chk(void*, const void*, long unsigned int, long unsigned int)’ writing 7 bytes into a region of size 6 [-Wstringop-overflow=]
  385 |   strcpy (ret, str);
      |          ^
In function ‘char* copy_to_non_const(const char*)’,
    inlined from ‘int main(int, char**)’ at octave-pserver.cc:640:39:
octave-pserver.cc:383:37: note: destination object of size 6 allocated by ‘operator new []’
  383 |   char *ret = new char [strlen (str)];
      |                                     ^
install -D octave-pserver ../bin/octave-pserver
rm network_set.bin MFDOCSTRINGS pconnect.bin __rfeval_slave__.bin reval.bin parcellfun_set_nproc.bin sclose.bin __parcellfun_get_next_result__.bin select_sockets.bin fsave.bin psend.bin parallel_generate_srp_data.bin precv.bin __exit__.bin __parcellfun_set_nproc_used__.bin select.bin __exit__.o fload.bin __parcellfun_initialize_job__.bin network_get_info.bin __parcellfun_send_next_args__.bin
make[1]: Leaving directory '/tmp/oct-GUHvFv/octave-parallel-4.0.2/src'

error: pkg: error running 'make' for the parallel package
error: called from
    configure_make at line 121 column 9
    install at line 202 column 7
    pkg at line 692 column 9
    /usr/share/dh-octave/install-pkg.m at line 45 column 1
dh_auto_install: error: octave --no-gui --no-history --silent --no-init-file --no-window-system /usr/share/dh-octave/install-pkg.m /build/reproducible-path/octave-parallel-4.0.2/debian/octave-parallel/usr/share/octave/packages /build/reproducible-path/octave-parallel-4.0.2/debian/octave-parallel/usr/lib/aarch64-linux-gnu/octave/packages returned exit code 1
make: *** [debian/rules:9: binary] Error 25
dpkg-buildpackage: error: debian/rules binary subprocess failed with exit status 2