Bug#1097479: nrn-mod2c: ftbfs with GCC-15

[Matthias Klose]

Package: src:nrn-mod2c
Version: 0.9+git220919-2
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/nrn-mod2c_0.9+git220919-2_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/nrn-mod2c-0.9+git220919/src/mod2c_core/nmodlfunc.h:113:6: note: declared here
  113 | void threadsafe();
      |      ^~~~~~~~~~
/build/reproducible-path/nrn-mod2c-0.9+git220919/src/mod2c_core/nocpout.c: At top level:
/build/reproducible-path/nrn-mod2c-0.9+git220919/src/mod2c_core/nocpout.c:3458:6: error: conflicting types for ‘threadsafe_seen’; have ‘void(Item *, Item *)’
 3458 | void threadsafe_seen(Item* q1, Item* q2) {
      |      ^~~~~~~~~~~~~~~
/build/reproducible-path/nrn-mod2c-0.9+git220919/src/mod2c_core/nmodlfunc.h:92:6: note: previous declaration of ‘threadsafe_seen’ with type ‘void(void)’
   92 | void threadsafe_seen();
      |      ^~~~~~~~~~~~~~~
/build/reproducible-path/nrn-mod2c-0.9+git220919/src/mod2c_core/nocpout.c: In function ‘conductance_hint’:
/build/reproducible-path/nrn-mod2c-0.9+git220919/src/mod2c_core/nocpout.c:3471:17: error: too many arguments to function ‘diag’; expected 0, have 2
 3471 |                 diag("CONDUCTANCE can only appear in BREAKPOINT block", (char*)0);
      |                 ^~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/build/reproducible-path/nrn-mod2c-0.9+git220919/src/mod2c_core/nmodlfunc.h:33:6: note: declared here
   33 | void diag();
      |      ^~~~
/build/reproducible-path/nrn-mod2c-0.9+git220919/src/mod2c_core/nocpout.c:3476:9: error: too many arguments to function ‘lappendsym’; expected 0, have 2
 3476 |         lappendsym(conductance_, SYM(q1->next));
      |         ^~~~~~~~~~ ~~~~~~~~~~~~
/build/reproducible-path/nrn-mod2c-0.9+git220919/src/mod2c_core/modl.h:230:18: note: declared here
  230 |                 *lappendsym(),
      |                  ^~~~~~~~~~
/build/reproducible-path/nrn-mod2c-0.9+git220919/src/mod2c_core/nocpout.c:3480:25: error: too many arguments to function ‘diag’; expected 0, have 2
 3480 |                         diag(s->name, " not declared as USEION in NEURON block");
      |                         ^~~~ ~~~~~~~
/build/reproducible-path/nrn-mod2c-0.9+git220919/src/mod2c_core/nmodlfunc.h:33:6: note: declared here
   33 | void diag();
      |      ^~~~
/build/reproducible-path/nrn-mod2c-0.9+git220919/src/mod2c_core/nocpout.c:3482:17: error: too many arguments to function ‘lappendsym’; expected 0, have 2
 3482 |                 lappendsym(conductance_, s);
      |                 ^~~~~~~~~~ ~~~~~~~~~~~~
/build/reproducible-path/nrn-mod2c-0.9+git220919/src/mod2c_core/modl.h:230:18: note: declared here
  230 |                 *lappendsym(),
      |                  ^~~~~~~~~~
/build/reproducible-path/nrn-mod2c-0.9+git220919/src/mod2c_core/nocpout.c:3484:17: error: too many arguments to function ‘lappendsym’; expected 0, have 2
 3484 |                 lappendsym(conductance_, SYM0);
      |                 ^~~~~~~~~~ ~~~~~~~~~~~~
/build/reproducible-path/nrn-mod2c-0.9+git220919/src/mod2c_core/modl.h:230:18: note: declared here
  230 |                 *lappendsym(),
      |                  ^~~~~~~~~~
/build/reproducible-path/nrn-mod2c-0.9+git220919/src/mod2c_core/nocpout.c:3486:9: error: too many arguments to function ‘deltokens’; expected 0, have 2
 3486 |         deltokens(q1, q2);
      |         ^~~~~~~~~ ~~
/build/reproducible-path/nrn-mod2c-0.9+git220919/src/mod2c_core/nmodlfunc.h:60:6: note: declared here
   60 | void deltokens();
      |      ^~~~~~~~~
/build/reproducible-path/nrn-mod2c-0.9+git220919/src/mod2c_core/nocpout.c: In function ‘possible_local_current’:
/build/reproducible-path/nrn-mod2c-0.9+git220919/src/mod2c_core/nocpout.c:3499:33: error: too many arguments to function ‘lappendsym’; expected 0, have 2
 3499 |                                 lappendsym(breakpoint_local_current_, SYM(q));
      |                                 ^~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~
/build/reproducible-path/nrn-mod2c-0.9+git220919/src/mod2c_core/modl.h:230:18: note: declared here
  230 |                 *lappendsym(),
      |                  ^~~~~~~~~~
/build/reproducible-path/nrn-mod2c-0.9+git220919/src/mod2c_core/nocpout.c:3500:33: error: too many arguments to function ‘lappendsym’; expected 0, have 2
 3500 |                                 lappendsym(breakpoint_local_current_, SYM(q2));
      |                                 ^~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~
/build/reproducible-path/nrn-mod2c-0.9+git220919/src/mod2c_core/modl.h:230:18: note: declared here
  230 |                 *lappendsym(),
      |                  ^~~~~~~~~~
make[3]: *** [src/mod2c_core/CMakeFiles/mod2c_core.dir/build.make:143: src/mod2c_core/CMakeFiles/mod2c_core.dir/nocpout.c.o] Error 1
make[3]: Leaving directory '/build/reproducible-path/nrn-mod2c-0.9+git220919/obj-x86_64-linux-gnu'
make[2]: *** [CMakeFiles/Makefile2:1056: src/mod2c_core/CMakeFiles/mod2c_core.dir/all] Error 2
make[2]: Leaving directory '/build/reproducible-path/nrn-mod2c-0.9+git220919/obj-x86_64-linux-gnu'
make[1]: *** [Makefile:149: all] Error 2
make[1]: Leaving directory '/build/reproducible-path/nrn-mod2c-0.9+git220919/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:6: binary] Error 25
dpkg-buildpackage: error: debian/rules binary subprocess returned exit status 2