Bug 1301533

I ran into the same problem.  My up-to-date Fedora 22 works just fine (and mpi.mod is in /usr/include/mpich-x86_64, but mpi up-to-date Fedora 23 fails to find mpi.mod (it is placed instead in /usr/lib64/gfortran/modules/mpich

Note that the environment variable MPI_FORTRAN_MOD_DIR points to the correct location for both F22 and F23.

this is still a bug on F24.  I am able to fix this by editing mpif90 directly, and changing the line

modincdir=/usr/include/mpich-x86_64

to read

modincdir=/usr/lib64/gfortran/modules/mpich


as a simple test program, use:

test.f90:
```
program test

  use mpi

  print *, "hello"

end program test
```

and compile as:

mpif90 -o test test.f90

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this still exists in F24 -- I don't seem to be able to change the version

Bug confirmed in Fedora 25.

Does anyone know what is blocking the (rather trivial) fix for this bug?

I confirm this on Fedora 25.

$ rpm -q mpich-devel
mpich-devel-3.2-6.fc25.x86_64
$ rpm -ql mpich-devel | grep 'mod$'
/usr/lib64/gfortran/modules/mpich/mpi.mod
/usr/lib64/gfortran/modules/mpich/mpi_base.mod
/usr/lib64/gfortran/modules/mpich/mpi_constants.mod
/usr/lib64/gfortran/modules/mpich/mpi_sizeofs.mod

$ module purge
$ module load mpi/mpich-x86_64
$  mpif90 -o test test.f90 
f951: Warning: Nonexistent include directory ‘/usr/include/mpich-x86_64’ [-Wmissing-include-dirs]
f951: Warning: Nonexistent include directory ‘/usr/include/mpich-x86_64’ [-Wmissing-include-dirs]
test.f90:3:6:

   use mpi
      1
Fatal Error: Can't open module file ‘mpi.mod’ for reading at (1): No such file or directory

On the contrary openmpi does not exhibit the problem, but packages mod files also under /usr/lib64/openmpi/lib:
$ ls -al /usr/lib64/openmpi/lib/mpi.mod /usr/lib64/gfortran/modules/openmpi/mpi.mod
lrwxrwxrwx. 1 root root    28 Oct 24 18:36 /usr/lib64/gfortran/modules/openmpi/mpi.mod -> ../../../openmpi/lib/mpi.mod
-rwxr-xr-x. 1 root root 81753 Oct 24 18:35 /usr/lib64/openmpi/lib/mpi.mod

As you say, no problem on el7 with mpich-3.0-devel-3.0.4-10.el7.x86_64, but that's because mpich on el7 still ships mpich mod files under /usr/include/mpich-x86_64:
$ rpm -ql mpich-3.0-devel | grep 'mod$'
/usr/include/mpich-x86_64/mpi.mod
/usr/include/mpich-x86_64/mpi_base.mod
/usr/include/mpich-x86_64/mpi_constants.mod
/usr/include/mpich-x86_64/mpi_sizeofs.mod
and openmpi does it also the "old way":
$ rpm -ql openmpi-devel | grep 'mod$'
/usr/lib64/openmpi/lib/mpi.mod

The troubles we see are due to the effort
(bug #1154982 bug #1154991) of trying to comply with https://fedoraproject.org/wiki/Packaging:MPI which states:

MPI_FORTRAN_MOD_DIR	%{_fmoddir}/%{name}	MPI stack specific Fortran module directory

A quick workaround would consist of providing links under /usr/include/mpich-x86_64 as openmpi on Fedora does, but that leaves mod files in two locations.

The choice of the location for the mod files affects also other applications see bug #1409229

mpich-3.2.1-2.fc27 has been pushed to the Fedora 27 testing repository. If problems still persist, please make note of it in this bug report.
See https://fedoraproject.org/wiki/QA:Updates_Testing for
instructions on how to install test updates.
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2017-18c6e5ac40

This message is a reminder that Fedora 25 is nearing its end of life.
Approximately 4 (four) weeks from now Fedora will stop maintaining
and issuing updates for Fedora 25. It is Fedora's policy to close all
bug reports from releases that are no longer maintained. At that time
this bug will be closed as EOL if it remains open with a Fedora  'version'
of '25'.

Package Maintainer: If you wish for this bug to remain open because you
plan to fix it in a currently maintained version, simply change the 'version'
to a later Fedora version.

Thank you for reporting this issue and we are sorry that we were not
able to fix it before Fedora 25 is end of life. If you would still like
to see this bug fixed and are able to reproduce it against a later version
of Fedora, you are encouraged  change the 'version' to a later Fedora
version prior this bug is closed as described in the policy above.

Although we aim to fix as many bugs as possible during every release's
lifetime, sometimes those efforts are overtaken by events. Often a
more recent Fedora release includes newer upstream software that fixes
bugs or makes them obsolete.

mpich-3.2.1-2.fc27 works, so I confirm this is fixed now (in updates-testing)

mpich-3.2.1-2.fc27 has been pushed to the Fedora 27 stable repository. If problems still persist, please make note of it in this bug report.