Dear maintainer:

During a rebuild of all packages in unstable, this package failed to build.

Below you will find the last part of the build log (probably the most
relevant part, but not necessarily). If required, the full build log
is available here:

https://people.debian.org/~sanvila/build-logs/202606/

About the archive rebuild: The build was made on virtual machines from AWS,
using sbuild and a reduced chroot with only build-essential packages.

If you cannot reproduce the bug please contact me privately, as I
am willing to provide ssh access to a virtual machine where the bug is
fully reproducible.

If this is really a bug in one of the build-depends, please use
reassign and add an affects on src:hypre, so that this is still
visible in the BTS web page for this package.

Thanks.
--------------------------------------------------------------------------------
[...]
Making utilities ...
make[3]: Entering directory '/<<PKGBUILDDIR>>/src/utilities'
x86_64-linux-gnu-gcc -g -O2 -Werror=implicit-function-declaration -ffile-prefix-map=/<<PKGBUILDDIR>>=. -fstack-protector-strong -fstack-clash-protection -Wformat -Werror=format-security -fcf-protection -Wall -pedantic -O3  -fPIC -DHAVE_CONFIG_H -I.. -I./.. -I./../struct_mv -I.          -I/usr/lib/x86_64-linux-gnu/openmpi/lib/../../fortran/gfortran-mod-16/openmpi  -c F90_HYPRE_error.c
x86_64-linux-gnu-gcc -g -O2 -Werror=implicit-function-declaration -ffile-prefix-map=/<<PKGBUILDDIR>>=. -fstack-protector-strong -fstack-clash-protection -Wformat -Werror=format-security -fcf-protection -Wall -pedantic -O3  -fPIC -DHAVE_CONFIG_H -I.. -I./.. -I./../struct_mv -I.          -I/usr/lib/x86_64-linux-gnu/openmpi/lib/../../fortran/gfortran-mod-16/openmpi  -c F90_HYPRE_general.c
In file included from _hypre_utilities.h:7,
                 from F90_HYPRE_general.c:8:
HYPRE_utilities.h:20:10: fatal error: mpi.h: No such file or directory
   20 | #include "mpi.h"
      |          ^~~~~~~
In file included from _hypre_utilities.h:7,
                 from F90_HYPRE_error.c:8:
HYPRE_utilities.h:20:10: fatal error: mpi.h: No such file or directory
   20 | #include "mpi.h"
      |          ^~~~~~~
compilation terminated.
compilation terminated.
make[3]: *** [../config/Makefile.config:55: F90_HYPRE_general.o] Error 1
make[3]: *** Waiting for unfinished jobs....
make[3]: *** [../config/Makefile.config:55: F90_HYPRE_error.o] Error 1
make[3]: Leaving directory '/<<PKGBUILDDIR>>/src/utilities'
make[2]: *** [Makefile:91: all] Error 1
make[2]: Leaving directory '/<<PKGBUILDDIR>>/src'
dh_auto_build: error: cd src && make -j2 returned exit code 2
make[1]: *** [debian/rules:152: override_dh_auto_build] Error 25
make[1]: Leaving directory '/<<PKGBUILDDIR>>'
make: *** [debian/rules:25: binary] Error 2
dpkg-buildpackage: error: debian/rules binary subprocess failed with exit status 2
--------------------------------------------------------------------------------

mpi.h comes from MPI (libopenmpi-dev), and hypre was previously
able to find it using the standard mpi configuration methods.

The problem is reproducible at
https://tests.reproducible-builds.org/debian/rb-pkg/unstable/amd64/hypre.html

I might have though that an openmpi update introduced a bug that
needs to be fixed, but it has no recent updates.

We'll have to dig a little to understand what's changed.

This may be related to the following change in debhelper 13.32.  See
also #1139889 [1].

 [ Helmut Grohne ]
 * autoconf: export standard build tools


[1] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1139889

Yes it is related, if e.g. $CC is set ./configure will not search for
e.g. mpigcc.
if test "x$CC" = "x"
then
   hypre_user_chose_ccompilers=no
...


Also debian/rules only passes the first directory of "pkg-config
--cflags-only-I mpi" to --with-MPI-include and of top of that
AC_HYPRE_CHECK_MPI and AC_CHECK_FUNCS([MPI_Comm_f2c] ignore $MPIINCLUDE
which was set by --with-MPI-include.

cu Andreas