Hi,

p4est 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/p4est_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.

[...]


datadir='${datarootdir}'
datarootdir='${prefix}/share'
docdir='${datarootdir}/doc/${PACKAGE_TARNAME}'
dvidir='${docdir}'
exec_prefix='NONE'
host=''
host_alias=''
host_cpu=''
host_os=''
host_vendor=''
htmldir='${docdir}'
includedir='${prefix}/include'
infodir='${prefix}/share/info'
install_sh='${SHELL} /build/reproducible-path/p4est-2.3.6/build-aux/install-sh'
libdir='${prefix}/lib/aarch64-linux-gnu'
libexecdir='${exec_prefix}/libexec'
localedir='${datarootdir}/locale'
localstatedir='/var'
mandir='${prefix}/share/man'
mkdir_p='$(MKDIR_P)'
oldincludedir='/usr/include'
pdfdir='${docdir}'
pkgconfigdir='${libdir}/pkgconfig'
prefix='/usr'
program_transform_name='s,x,x,'
psdir='${docdir}'
runstatedir='/run'
sbindir='${exec_prefix}/sbin'
sharedstatedir='${prefix}/com'
subdirs=''
sysconfdir='/etc'
target_alias=''

## ----------- ##
## confdefs.h. ##
## ----------- ##

/* confdefs.h */
#define PACKAGE_NAME "p4est"
#define PACKAGE_TARNAME "p4est"
#define PACKAGE_VERSION "2.3.6"
#define PACKAGE_STRING "p4est 2.3.6"
#define PACKAGE_BUGREPORT "p4est@ins.uni-bonn.de"
#define PACKAGE_URL ""
#define PACKAGE "p4est"
#define VERSION "2.3.6"
#define VERSION_MAJOR 2
#define VERSION_MINOR 3
#define VERSION_POINT 6
#define VTK_BINARY 1
#define ENABLE_VTK_BINARY 1
#define VTK_COMPRESSION 1
#define ENABLE_VTK_COMPRESSION 1
#define BUILD_2D 1
#define ENABLE_BUILD_2D 1
#define BUILD_3D 1
#define ENABLE_BUILD_3D 1
#define BUILD_P6EST 1
#define ENABLE_BUILD_P6EST 1
#define MPI 1
#define ENABLE_MPI 1
#define MPIIO 1
#define ENABLE_MPIIO 1
#define ENABLE_MPITHREAD 1

configure: exit 77
dh_auto_configure: error: ./configure --build=aarch64-linux-gnu --prefix=/usr --includedir=\${prefix}/include --mandir=\${prefix}/share/man --infodir=\${prefix}/share/info --sysconfdir=/etc --localstatedir=/var --disable-option-checking --disable-silent-rules --libdir=\${prefix}/lib/aarch64-linux-gnu --runstatedir=/run --disable-maintainer-mode --disable-dependency-tracking --enable-mpi --enable-mpiio returned exit code 77
make[1]: *** [debian/rules:17: override_dh_auto_configure] Error 25
make[1]: Leaving directory '/build/reproducible-path/p4est-2.3.6'
make: *** [debian/rules:9: binary] Error 2
dpkg-buildpackage: error: debian/rules binary subprocess failed with exit status 2

Hi.

The real error is this:

checking whether the Fortran 77 compiler works... no
configure: error: in '/build/reproducible-path/p4est-2.3.6':
configure: error: Fortran 77 compiler cannot create executables
See 'config.log' for more details
        tail -v -n \+0 config.log
==> config.log <==

(This is one of those cases where providing just the final part of the
build log hides the real issue, and one of the problems I have to
face when reporting ftbfs bugs myself).

Thanks.

Dear maintainer,

I've prepared an NMU for p4est (versioned as 2.3.6-2.1) and uploaded
it to DELAYED/14. Please feel free to tell me if I should cancel it.

cu
Adrian

Sorry, wrong bug number.

cu
Adrian