Following command will fail:
/usr/local/Cellar/bash/5.0.11/bin/bash test_jpackage.sh -t PATH_TO_JDK -o output
test_jpackage.sh: line 72: ./run_tests.sh: Permission denied

Patching test_jpackage.sh as following:
-exec_command "$basedir/run_tests.sh" -m create "${args[@]}"
+exec_command $SHELL "$basedir/run_tests.sh" -m create "${args[@]}"

with export SHELL=/usr/local/Cellar/bash/5.0.11/bin/bash

will fails with error:
xargs: illegal option -- -
usage: xargs [-0opt] [-E eofstr] [-I replstr [-R replacements]] [-J replstr]
             [-L number] [-n number [-x]] [-P maxprocs] [-s size]
             [utility [argument ...]]

Looks like macOS xargs version does not support --no-run-if-empty.