[MPIPreferences] Allow passing extra dirs to use_system_binary (#832)

Author: giordano

.github/workflows/UnitTests.yml

@@ -165,10 +165,7 @@ jobs:
 
     - name: Install MPI via homebrew
       run: |
-        brew install "${MPI}"
-        echo "DYLD_FALLBACK_LIBRARY_PATH=$(brew --prefix ${MPI})/lib" >> "${GITHUB_ENV}"
-      env:
-        MPI: ${{ matrix.mpi }}
+        brew install "${{ matrix.mpi }}"
 
     - uses: julia-actions/setup-julia@v1
       with:
@@ -186,7 +183,9 @@ jobs:
       shell: julia --color=yes --project=. {0}
       run: |
         using MPIPreferences
-        MPIPreferences.use_system_binary()
+        mpi_prefix = readchomp(`brew --prefix ${{ matrix.mpi }}`)
+        libdir = joinpath(mpi_prefix, "lib")
+        MPIPreferences.use_system_binary(; extra_paths=[libdir])
 
     - uses: julia-actions/julia-runtest@v1
       env:

lib/MPIPreferences/Project.toml

@@ -1,7 +1,7 @@
 name = "MPIPreferences"
 uuid = "3da0fdf6-3ccc-4f1b-acd9-58baa6c99267"
 authors = []
-version = "0.1.10"
+version = "0.1.11"
 
 [deps]
 Libdl = "8f399da3-3557-5675-b5ff-fb832c97cbdb"

lib/MPIPreferences/src/MPIPreferences.jl

@@ -119,6 +119,7 @@ end
 """
     use_system_binary(;
         library_names = ["libmpi", "libmpi_ibm", "msmpi", "libmpich", "libmpi_cray", "libmpitrampoline"],
+        extra_paths = String[],
         mpiexec = "mpiexec",
         abi = nothing,
         vendor = nothing,
@@ -135,6 +136,9 @@ Options:
   If the library isn't in the library search path, you can specify the full path
   to the library.
 
+- `extra_paths`: indicate extra directories where to search for the MPI library,
+  besides the default ones of the dynamic linker.
+
 - `mpiexec`: the MPI launcher executable. The default is `mpiexec`, but some
   clusters require using the scheduler launcher interface (e.g. `srun` on Slurm,
   `aprun` on PBS). It is also possible to pass a [`Cmd`
@@ -159,6 +163,7 @@ Options:
 """
 function use_system_binary(;
         library_names=["libmpi", "libmpi_ibm", "msmpi", "libmpich", "libmpi_cray", "libmpitrampoline"],
+        extra_paths=String[],
         mpiexec="mpiexec",
         abi=nothing,
         vendor=nothing,
@@ -186,12 +191,14 @@ function use_system_binary(;
 
     # Set `ZES_ENABLE_SYSMAN` to work around https://github.com/open-mpi/ompi/issues/10142
     libmpi = withenv("ZES_ENABLE_SYSMAN" => "1") do
-        find_library(library_names)
+        find_library(library_names, extra_paths)
     end
     if libmpi == ""
         error("""
             MPI library could not be found with the following name(s):
                 $(library_names)
+            in the following extra directories (in addition to the default ones):
+                $(extra_paths)
             If you want to try different name(s) for the MPI library, use
                 MPIPreferences.use_system_binary(; library_names=[...])""")
     end