Bug#1097455: neuron: ftbfs with GCC-15

[Matthias Klose]

Package: src:neuron
Version: 8.2.2-7
Severity: important
Tags: sid forky
User: debian-gcc at lists.debian.org
Usertags: ftbfs-gcc-15

[This bug is NOT targeted to the upcoming trixie release]

Please keep this issue open in the bug tracker for the package it
was filed for.  If a fix in another package is required, please
file a bug for the other package (or clone), and add a block in this
package. Please keep the issue open until the package can be built in
a follow-up test rebuild.

The package fails to build in a test rebuild on at least amd64 with
gcc-15/g++-15, but succeeds to build with gcc-14/g++-14. The
severity of this report will be raised before the forky release.

The full build log can be found at:
http://qa-logs.debian.net/2025/02/16/amd64exp/neuron_8.2.2-7_unstable_gccexp.log.gz
The last lines of the build log are at the end of this report.

To build with GCC 15, either set CC=gcc-15 CXX=g++-15 explicitly,
or install the gcc, g++, gfortran, ... packages from experimental.

  apt-get -t=experimental install g++ 

GCC 15 now defaults to the C23/C++23 standards, exposing many FTBFS.
Other Common build failures are new warnings resulting in build failures
with -Werror turned on, or new/dropped symbols in Debian symbols files.
For other C/C++ related build failures see the porting guide at
http://gcc.gnu.org/gcc-15/porting_to.html

[...]
/build/reproducible-path/neuron-8.2.2/src/mesch/arnoldi.c: In function ‘gmres’:
/build/reproducible-path/neuron-8.2.2/src/mesch/arnoldi.c:121:10: warning: old-style function definition [-Wold-style-definition]
  121 | VEC     *gmres(A,A_param,m,Q,R,b,tol,x)
      |          ^~~~~
In file included from /build/reproducible-path/neuron-8.2.2/src/mesch/matrix.h:47,
                 from /build/reproducible-path/neuron-8.2.2/src/mesch/arnoldi.c:33:
/build/reproducible-path/neuron-8.2.2/src/mesch/arnoldi.c:162:25: error: too many arguments to function ‘A’; expected 0, have 3
  162 |         tracecatch(u = (*A)(A_param,v,u),"gmres");
      |                        ~^~~ ~~~~~~~
/build/reproducible-path/neuron-8.2.2/src/mesch/err.h:171:25: note: in definition of macro ‘tracecatch’
  171 |                 {       ok_part; \
      |                         ^~~~~~~
make[3]: *** [src/nrniv/CMakeFiles/nrniv_lib.dir/build.make:2598: src/nrniv/CMakeFiles/nrniv_lib.dir/__/mesch/arnoldi.c.o] Error 1
make[3]: *** Waiting for unfinished jobs....
/build/reproducible-path/neuron-8.2.2/src/mesch/bdfactor.c: In function ‘bd_get’:
/build/reproducible-path/neuron-8.2.2/src/mesch/bdfactor.c:53:7: warning: old-style function definition [-Wold-style-definition]
   53 | BAND *bd_get(lb,ub,n)
      |       ^~~~~~
/build/reproducible-path/neuron-8.2.2/src/mesch/bdfactor.c: In function ‘bd_free’:
/build/reproducible-path/neuron-8.2.2/src/mesch/bdfactor.c:74:5: warning: old-style function definition [-Wold-style-definition]
   74 | int bd_free(A)
      |     ^~~~~~~
/build/reproducible-path/neuron-8.2.2/src/mesch/bdfactor.c: In function ‘bd_resize’:
/build/reproducible-path/neuron-8.2.2/src/mesch/bdfactor.c:95:7: warning: old-style function definition [-Wold-style-definition]
   95 | BAND *bd_resize(A,new_lb,new_ub,new_n)
      |       ^~~~~~~~~
/build/reproducible-path/neuron-8.2.2/src/mesch/bdfactor.c: In function ‘bd_copy’:
/build/reproducible-path/neuron-8.2.2/src/mesch/bdfactor.c:156:7: warning: old-style function definition [-Wold-style-definition]
  156 | BAND *bd_copy(A,B)
      |       ^~~~~~~
/build/reproducible-path/neuron-8.2.2/src/mesch/bdfactor.c: In function ‘band2mat’:
/build/reproducible-path/neuron-8.2.2/src/mesch/bdfactor.c:187:6: warning: old-style function definition [-Wold-style-definition]
  187 | MAT *band2mat(bA,A)
      |      ^~~~~~~~
/build/reproducible-path/neuron-8.2.2/src/mesch/bdfactor.c: In function ‘mat2band’:
/build/reproducible-path/neuron-8.2.2/src/mesch/bdfactor.c:218:7: warning: old-style function definition [-Wold-style-definition]
  218 | BAND *mat2band(A,lb,ub,bA)
      |       ^~~~~~~~
/build/reproducible-path/neuron-8.2.2/src/mesch/bdfactor.c: In function ‘bd_transp’:
/build/reproducible-path/neuron-8.2.2/src/mesch/bdfactor.c:253:7: warning: old-style function definition [-Wold-style-definition]
  253 | BAND *bd_transp(in,out)
      |       ^~~~~~~~~
/build/reproducible-path/neuron-8.2.2/src/mesch/bdfactor.c: In function ‘bdLUfactor’:
/build/reproducible-path/neuron-8.2.2/src/mesch/bdfactor.c:366:10: warning: old-style function definition [-Wold-style-definition]
  366 | BAND    *bdLUfactor(bA,pivot)
      |          ^~~~~~~~~~
/build/reproducible-path/neuron-8.2.2/src/mesch/bdfactor.c: In function ‘bdLUsolve’:
/build/reproducible-path/neuron-8.2.2/src/mesch/bdfactor.c:449:10: warning: old-style function definition [-Wold-style-definition]
  449 | VEC     *bdLUsolve(bA,pivot,b,x)
      |          ^~~~~~~~~
/build/reproducible-path/neuron-8.2.2/src/mesch/bdfactor.c: In function ‘bdLDLfactor’:
/build/reproducible-path/neuron-8.2.2/src/mesch/bdfactor.c:507:7: warning: old-style function definition [-Wold-style-definition]
  507 | BAND *bdLDLfactor(A)
      |       ^~~~~~~~~~~
/build/reproducible-path/neuron-8.2.2/src/mesch/bdfactor.c: In function ‘bdLDLsolve’:
/build/reproducible-path/neuron-8.2.2/src/mesch/bdfactor.c:554:9: warning: old-style function definition [-Wold-style-definition]
  554 | VEC    *bdLDLsolve(A,b,x)
      |         ^~~~~~~~~~
/build/reproducible-path/neuron-8.2.2/src/mesch/bdfactor.c: In function ‘bd_mv_mlt’:
/build/reproducible-path/neuron-8.2.2/src/mesch/bdfactor.c:613:6: warning: old-style function definition [-Wold-style-definition]
  613 | VEC *bd_mv_mlt(A, x, out)
      |      ^~~~~~~~~
make[3]: Leaving directory '/build/reproducible-path/neuron-8.2.2/obj-x86_64-linux-gnu'
make[2]: *** [CMakeFiles/Makefile2:534: src/nrniv/CMakeFiles/nrniv_lib.dir/all] Error 2
make[2]: Leaving directory '/build/reproducible-path/neuron-8.2.2/obj-x86_64-linux-gnu'
make[1]: *** [Makefile:139: all] Error 2
make[1]: Leaving directory '/build/reproducible-path/neuron-8.2.2/obj-x86_64-linux-gnu'
dh_auto_build: error: cd obj-x86_64-linux-gnu && make -j8 "INSTALL=install --strip-program=true" VERBOSE=1 returned exit code 2
make: *** [debian/rules:22: binary] Error 25
dpkg-buildpackage: error: debian/rules binary subprocess returned exit status 2