Log Message:
parallel/mpi-ch: update to 3.4.3

This also removes the MPI_PREFIX business. No parallel installation of multiple
MPIs intended right now. Also, the f90 option is default now to support upcoming
parallel-computing packages in the default setup.

===============================================================================
                               Changes in 3.4.3
===============================================================================

# Fix bugs in GPFS ROMIO driver

# Fix bugs in DAOS ROMIO driver

# Fix nemesis shm bug on systems with weak memory consistency

# Fix progress issue in ch4:ucx finalize

# Fix nonblocking collective issue during finalize

# Fix UBSan warnings in 32-bit builds

# Fix predefined datatype handle leaks

# Fix bug in topology-aware communicator creation

# Fix Slurm nodelist parsing

# Fix testcase for out-of-tree configuration

# Fix truncation testcase for possible disconnection error

# Hydra help message improvements

# Add support for DAOS pool and container labels

===============================================================================
                               Changes in 3.4.2
===============================================================================

# Update configure options to support --disable-ze and --disable-cuda
  to explicitly disable GPU-awareness

# Update embedded hwloc to version 2.4.1. Fixes a build issue on
  systems with OpenCL.

# Fixes for Argobots thread package support.

# Fixes for the DAOS ROMIO driver (thanks to Intel for contributing)

# Fix additional bugs in GPU-aware nonblocking op collectives

# Fix 'make check' errors with embedded MPL and json-c libraries

# Fix support for GNI provider in ch4:ofi netmod

# Fix bug in dynamic window memory registration with ch4:ofi netmod

# Fix bug in persistent pt2pt when used with MPI_PROC_NULL

# Fix bug in hydra nameserver when freeing published entries

# Fix bugs in GPFS ROMIO driver (thanks to IBM for contributing)

# Fix bug in darray type creation (thanks to IBM for contributing)

# Fix bugs in XPMEM support

# Fix bug in MPI_Comm_spawn_multiple where non-root args were not ignored

===============================================================================
                               Changes in 3.4.1
===============================================================================

# Fix bug in GPU memory hooks that caused failures with NCCL

# Fix bug in GPU-aware nonblocking op collectives

# Hide symbols from embedded json-c module

# Removed anonymous struct/union usage in MPL

# Disable Java support in embedded UCX module

===============================================================================
                               Changes in 3.4
===============================================================================

# ch4 replaces ch3 as the default device configuration. If no network
  module is specified at configuration-time, MPICH will search the
  user environment in order to select one to build. The user will be
  prompted to choose if no preferred network library is detected.

# Add support for Yaksa datatype engine (default in ch4).

# Add support for GPU buffers (CUDA, Level Zero) in pt2pt,
  collectives, and one-sided communication.

# Add support for XPMEM.

# Add support for multiple virtual communication interfaces for more
  efficient MPI_THREAD_MULTIPLE (experimental).

# Add DAOS ADIO driver to ROMIO (contributed by Intel).

# Add Quobyte ADIO driver to ROMIO (contributed by Quobyte).

# Add support for Arm compiler toolchain

# Add support for NVIDIA HPC compilers

# Add support for flang/f18 Fortran compiler

# Add support for AddressSanitizer and UndefinedBehaviorSanitizer to
  debug configuration

# Remove mxm, llc, and portals4 netmods from ch3.

# Remove support for logical reduction operations on floating point
  types.

# Remove MPIX_Mutex interfaces.

# Further improvements to ch4 business card exchange: extra
  long address support and fixes for PMIx integration.

# Un-inline non-critical ch4 code for improved build times.

# Fix several test program bugs.

# Fix several static analysis and compiler warnings.

# Change the signature of MPID_Init to include requested and provided
  thread levels.

===============================================================================
                               Changes in 3.3.2
===============================================================================

# Add support for struct sockaddr in MPICH, Hydra, and PMI socket
  code. Works with both IPv4 and IPv6 addresses.

# Fix localhost detection on FreeBSD and macOS, avoiding long delay
  during startup.

# Fix thread-local storage detection.

# Fix several test program bugs.

# Fix several static analysis and compiler warnings.

===============================================================================
                               Changes in 3.3.1
===============================================================================

 # Fix bug in MPI_Testany/MPI_Waitany that could cause deadlock

 # Add missing functionality in Argobots library support

 # Fix configure-time detection for thread local storage support

 # Better support for reproducible builds. Thanks to Bernhard
   Wiedemann for the report and fixes

 # Fix support for XL compiler toolchain

 # Add support for -static-intel linking option

 # Fix building on systems without weak symbols

 # Fix several static analysis and compiler warnings

===============================================================================
                               Changes in 3.3
===============================================================================

 # CH4 Device: A new device layer implementation designed for low software
   overheads. CH4 has experimental support for OFI and UCX network libraries,
   and POSIX shared memory. Thanks to Intel, Mellanox, and RIKEN AICS for
   participating in the CH4 coding effort.

 # Fixed SLURM integration in Hydra for new node list format.

 # Added support for PMIx (https://pmix.github.io/pmix/) client
   library in CH4 netmods. Note that you must use a compatible PMIx
   server in this configuration.

 # Better organization of collectives in the MPI layer. The new
   scheme, which de-couples implementation from selection logic,
   enables easier integration of additional algorithms.

 # TSP collectives framework: A C++-template style framework for
   collective algorithms is added to allow single collective
   implementation to move data over generic or device-specific
   transport functions.

 # Improvements to derived datatype testing (DTPools -
   https://wiki.mpich.org/mpich/index.php/DTPools).

 # Added new "non-catastrophic" error codes to expose internal
   resource exhaustion.

 # Added info hints to MPI_Comm_split_type to support splitting
   communicators by machine topology. Both on-node (socket, core,
   etc.) and off-node (switch-level) hints are defined.

 # Improvements to MPI_THREAD_MULTIPLE in CH4 through new thread safety
   models at the Virtual Network Interface (VNI) level. This introduces two
   new models that leverage work-queues to offload operations and improve
   scalability under contention.

 # Message Driven Thread Activation (MDTA). An alternative locking
   model is defined for MPI_THREAD_MULTIPLE in CH4.

 # Added PMI usage optimizations for business card exchange in CH4
   netmods.

 # Improvements on MPI_Abort. MPI_Abort invoked on subcommunicators will
   only abort the connected processes within that communicator.
`
 # Cleanup of whitespace (ch3 excluded) using the
   maint/code-cleanup.sh script. For instructions on how to update
   PRs/branches based on MPICH before the cleanup, see
   https://github.com/pmodels/mpich/wiki/Code-Cleanup-Procedure.

 # Removed the PAMI device and poe PMI client.

 # C99 compiler support is now required to build MPICH.

 # Several other minor bug fixes, memory leak fixes, and code cleanup.

   A full list of changes is available at the following link:

     http://git.mpich.org/mpich.git/shortlog/v3.2..v3.3

   A list of bugs that have been fixed is available at the following
   link:

     https://github.com/pmodels/mpich/milestone/25?closed=1