scalapack: ftbfs with GCC-15

Imported from Debian bug http://bugs.debian.org/1097848:

Package: src:scalapack
Version: 2.2.2-1
Severity: important
Tags: sid forky
User: <email address hidden>
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/scalapack_2.2.2-1_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

[...]
   17 | void Cblacs_get();
      | ^~~~~~~~~~
/build/reproducible-path/scalapack-2.2.2/TOOLS/reshape.c:73:4: error: too many arguments to function ‘Cblacs_gridmap’; expected 0, have 5
   73 | Cblacs_gridmap( context_out, grid_new, nprow_new, nprow_new, npcol_new );
      | ^~~~~~~~~~~~~~ ~~~~~~~~~~~
/build/reproducible-path/scalapack-2.2.2/TOOLS/reshape.c:18:9: note: declared here
   18 | void Cblacs_gridmap();
      | ^~~~~~~~~~~~~~
/build/reproducible-path/scalapack-2.2.2/TOOLS/reshape.c:21:11: warning: unused variable ‘j’ [-Wunused-variable]
   21 | Int i, j;
      | ^
/build/reproducible-path/scalapack-2.2.2/TOOLS/reshape.c: At top level:
/build/reproducible-path/scalapack-2.2.2/TOOLS/reshape.c:101:6: error: conflicting types for ‘proc_inc’; have ‘void(long int *, long int *, long int, long int, long int)’
  101 | void proc_inc( Int* myrow, Int* mycol, Int nprow, Int npcol, Int major )
      | ^~~~~~~~
/build/reproducible-path/scalapack-2.2.2/TOOLS/reshape.c:14:9: note: previous declaration of ‘proc_inc’ with type ‘void(void)’
   14 | void proc_inc();
      | ^~~~~~~~
make[4]: *** [CMakeFiles/scalapack.dir/build.make:4680: CMakeFiles/scalapack.dir/TOOLS/reshape.c.o] Error 1
make[4]: *** Waiting for unfinished jobs....
[ 15%] Building C object CMakeFiles/scalapack.dir/TOOLS/SL_gridreshape.c.o
/usr/bin/cc -DAdd_ -Dscalapack_EXPORTS -isystem /usr/lib/x86_64-linux-gnu/mpich/include -g -O2 -Wno-error=implicit-function-declaration -ffile-prefix-map=/build/reproducible-path/scalapack-2.2.2=. -fstack-protector-strong -fstack-clash-protection -Wformat -Werror=format-security -fcf-protection -Wall -pedantic -DInt=long -fPIC -MD -MT CMakeFiles/scalapack.dir/TOOLS/SL_gridreshape.c.o -MF CMakeFiles/scalapack.dir/TOOLS/SL_gridreshape.c.o.d -o CMakeFiles/scalapack.dir/TOOLS/SL_gridreshape.c.o -c /build/reproducible-path/scalapack-2.2.2/TOOLS/SL_gridreshape.c
/build/reproducible-path/scalapack-2.2.2/TOOLS/SL_gridreshape.c: In function ‘SL_Cgridreshape’:
/build/reproducible-path/scalapack-2.2.2/TOOLS/SL_gridreshape.c:13:4: warning: implicit declaration of function ‘Cblacs_gridinfo’ [-Wimplicit-function-declaration]
   13 | Cblacs_gridinfo(ctxt, &P0, &Q0, &i, &Np);
      | ^~~~~~~~~~~~~~~
/build/reproducible-path/scalapack-2.2.2/TOOLS/SL_gridreshape.c:18:7: warning: implicit declaration of function ‘Cblacs_abort’ [-Wimplicit-function-declaration]
   18 | Cblacs_abort(ctxt, -22);
      | ^~~~~~~~~~~~
/build/reproducible-path/scalapack-2.2.2/TOOLS/SL_gridreshape.c:30:30: error: too many arguments to function ‘Cblacs_pnum’; expected 0, have 3
   30 | g[(i%Q)*P+i/Q] = Cblacs_pnum(ctxt, (pstart+i)/Q0, (pstart+i)%Q0);
      | ^~~~~~~~~~~ ~~~~
/build/reproducible-path/scalapack-2.2.2/TOOLS/SL_gridreshape.c:10:8: note: declared here
   10 | Int Cblacs_pnum();
      | ^~~~~~~~~~~
/build/reproducible-path/scalapack-2.2.2/TOOLS/SL_gridreshape.c:33:20: error: too many arguments to function ‘Cblacs_pnum’; expected 0, have 3
   33 | g[i] = Cblacs_pnum(ctxt, (pstart+i)/Q0, (pstart+i)%Q0);
      | ^~~~~~~~~~~ ~~~~
/build/reproducible-path/scalapack-2.2.2/TOOLS/SL_gridreshape.c:10:8: note: declared here
   10 | Int Cblacs_pnum();
      | ^~~~~~~~~~~
/build/reproducible-path/scalapack-2.2.2/TOOLS/SL_gridreshape.c:39:30: error: too many arguments to function ‘Cblacs_pnum’; expected 0, have 3
   39 | g[(i%Q)*P+i/Q] = Cblacs_pnum(ctxt, (pstart+i)%P0, (pstart+i)/P0);
      | ^~~~~~~~~~~ ~~~~
/build/reproducible-path/scalapack-2.2.2/TOOLS/SL_gridreshape.c:10:8: note: declared here
   10 | Int Cblacs_pnum();
      | ^~~~~~~~~~~
/build/reproducible-path/scalapack-2.2.2/TOOLS/SL_gridreshape.c:42:20: error: too many arguments to function ‘Cblacs_pnum’; expected 0, have 3
   42 | g[i] = Cblacs_pnum(ctxt, (pstart+i)%P0, (pstart+i)/P0);
      | ^~~~~~~~~~~ ~~~~
/build/reproducible-path/scalapack-2.2.2/TOOLS/SL_gridreshape.c:10:8: note: declared here
   10 | Int Cblacs_pnum();
      | ^~~~~~~~~~~
/build/reproducible-path/scalapack-2.2.2/TOOLS/SL_gridreshape.c:44:4: warning: implicit declaration of function ‘Cblacs_get’ [-Wimplicit-function-declaration]
   44 | Cblacs_get(ctxt, 10, &nctxt);
      | ^~~~~~~~~~
/build/reproducible-path/scalapack-2.2.2/TOOLS/SL_gridreshape.c:45:4: warning: implicit declaration of function ‘Cblacs_gridmap’ [-Wimplicit-function-declaration]
   45 | Cblacs_gridmap(&nctxt, g, P, P, Q);
      | ^~~~~~~~~~~~~~
make[4]: *** [CMakeFiles/scalapack.dir/build.make:4694: CMakeFiles/scalapack.dir/TOOLS/SL_gridreshape.c.o] Error 1
make[4]: Leaving directory '/build/reproducible-path/scalapack-2.2.2/build64-mpich'
make[3]: *** [CMakeFiles/Makefile2:1738: CMakeFiles/scalapack.dir/all] Error 2
make[3]: Leaving directory '/build/reproducible-path/scalapack-2.2.2/build64-mpich'
make[2]: *** [Makefile:169: all] Error 2
make[2]: Leaving directory '/build/reproducible-path/scalapack-2.2.2/build64-mpich'
dh_auto_build: error: cd build64-mpich && make -j8 "INSTALL=install --strip-program=true" VERBOSE=1 returned exit code 2
make[1]: *** [debian/rules:107: override_dh_auto_build-arch] Error 25
make[1]: Leaving directory '/build/reproducible-path/scalapack-2.2.2'
make: *** [debian/rules:50: binary] Error 2
dpkg-buildpackage: error: debian/rules binary subprocess returned exit status 2