Workaround for current CI issues with clang14 on MacOS (#1565)

* Use mpirun wrapper to circumvent parser bug in mpirun

The bug sounds similar to this one
open-mpi/ompi#6372, though that is supposedly
fixed in Open MPI 5..

This creates a tmp script to call the launched application instead of
calling it directly on the command line. This way, mpirun does not see
the command line arguments and cannot try to wrongly parse them.

* Add mechanism to get rid of the workaround again in future

.github/workflows/macos.yml

@@ -40,7 +40,8 @@ jobs:
           -DopenPMD_USE_MPI=ON    \
           -DopenPMD_USE_HDF5=ON   \
           -DopenPMD_USE_ADIOS2=ON \
-          -DopenPMD_USE_INVASIVE_TESTS=ON
+          -DopenPMD_USE_INVASIVE_TESTS=ON \
+          -DMPIEXEC_EXECUTABLE=".github/workflows/mpirun_workaround.sh"
         cmake --build build --parallel 3
         ctest --test-dir build --verbose
 

.github/workflows/mpirun_workaround.sh

@@ -0,0 +1,51 @@
+#!/usr/bin/env bash
+
+# mpiexec currently seems to have a bug where it tries to parse parameters
+# of the launched application when they start with a dash, e.g.
+# `mpiexec python ./openpmd-pipe --infile in.bp --outfile out.bp`
+# leads to:
+# >  An unrecognized option was included on the mpiexec command line:
+# >
+# >    Option: --infile
+# >
+# >  Please use the "mpiexec --help" command to obtain a list of all
+# >  supported options.
+#
+# This script provides a workaround by putting the called sub-command into
+# a script in a temporary file.
+
+mpiexec -n 1 ls --all \
+    && echo "MPIRUN WORKING AGAIN, PLEASE REMOVE WORKAROUND" >&2 \
+    && exit 1 \
+    || true
+
+mpirun_args=()
+
+script_file="$(mktemp)"
+
+cleanup() {
+    rm "$script_file"
+}
+trap cleanup EXIT
+
+while true; do
+    case "$1" in
+        -c | -np | --np | -n | --n )
+            mpirun_args+=("$1" "$2")
+            shift
+            shift
+            ;;
+        *)
+            break
+            ;;
+    esac
+done
+
+echo -e '#!/usr/bin/env bash\n' > "$script_file"
+for item in "$@"; do
+    echo -n "'$item' " >> "$script_file"
+done
+
+chmod +x "$script_file"
+
+mpirun "${mpirun_args[@]}" "$script_file"