Add RDMAV_FORK_SAFE=1 to avoid fork error with libfabric

.github/workflows/ci.yml

@@ -84,6 +84,10 @@ jobs:
       LIBMESH: ${{ matrix.libmesh }}
       NPY_DISABLE_CPU_FEATURES: "AVX512F AVX512_SKX"
       OPENBLAS_NUM_THREADS: 1
+      # libfabric complains about fork() as a result of using Python multiprocessing.
+      # We can work around it with RDMAV_FORK_SAFE=1 in libfabric < 1.13 and with
+      # FI_EFA_FORK_SAFE=1 in more recent versions.
+      RDMAV_FORK_SAFE: 1
 
     steps:
       - uses: actions/checkout@v3

tools/ci/gha-script.sh

@@ -8,7 +8,7 @@ args=" "
 if [[ $MPI == 'y' ]]; then
   args="${args} --mpi "
 fi
-  
+
 # Check for event-based
 if [[ $EVENT == 'y' ]]; then
   args="${args} --event "