Missing PMPI symbols for some Fortran 2008 calls

[gcorbin]

Background information

For context: I found this because I am developing a PMPI wrapper library for the Fortran 2008 bindings.

What version of Open MPI are you using? (e.g., v4.1.6, v5.0.1, git branch name and hash, etc.)

I see the bug with

• 5.0.4
• 5.0.6

With older versions (4.1) the bug is not present

Describe how Open MPI was installed (e.g., from a source/distribution tarball, from a git clone, from an operating system distribution package, etc.)

Installed from tarball on my local linux machine with a plain configure. Compiler is gcc/11.4

If you are building/installing from a git clone, please copy-n-paste the output from git submodule status.

n/a

Please describe the system on which you are running

• Operating system/version: Linux 6.8.0-49-generic x86_64
• Computer hardware: Laptop
• Network type: Linux shared memory + TCP enabled by configure, but probably not relevant to this issue

---

Details of the problem

Compiling the program below with mpif90 main.f90 results in a linker error:

/usr/bin/ld: /tmp/ccpw1Fqo.o: in function `MAIN__':
main.f90:(.text+0x63): undefined reference to `pmpi_allreduce_init_f08_'
/usr/bin/ld: main.f90:(.text+0x88): undefined reference to `pmpi_group_from_session_pset_f08_'
/usr/bin/ld: main.f90:(.text+0xa2): undefined reference to `pmpi_session_call_errhandler_f08_'

program main
! This program is not intended to run correctly.
! Its purpose is to trigger undefined reference errors when compiled with OpenMPI/5.0.x
    use :: mpi_f08, only: &
        PMPI_Allreduce_init, MPI_Request, MPI_REAL, MPI_SUM, MPI_COMM_WORLD, MPI_INFO_NULL, &
        PMPI_Group_from_session_pset, MPI_Session, MPI_Group, &
        PMPI_Session_call_errhandler, MPI_SUCCESS

    implicit none

    integer, parameter :: nbuf = 10
    real, dimension(nbuf) :: sendbuf, recvbuf
    type(MPI_Request) :: request

    type(MPI_Session) :: session
    type(MPI_Group) :: group
    integer :: ierror

    call PMPI_Allreduce_init(sendbuf, &
        recvbuf, &
        nbuf, &
        MPI_REAL, &
        MPI_SUM, &
        MPI_COMM_WORLD, &
        MPI_INFO_NULL, &
        request, &
        ierror)

    call PMPI_Group_from_session_pset(session, "group", group, ierror)

    call PMPI_Session_call_errhandler(session, MPI_SUCCESS, ierror)
end program

Symbols for

• PMPI_Allreduce_init,
• PMPI_Group_from_session_pset,
• PMPI_Session_call_errhandler

are missing .

The names are present in the mpi_f08 module, because otherwise the compiler would complain about not finding them.

[jsquyres]

@gcorbin Many thanks for reporting the problem!

I have filed a fix in #12956.