ARC 6 build error on Debian 9 related to slurm tests

Build fails for ARC 6 on Debian 9 with:

make[8]: Entering directory '/builds/nordugrid/arc/src/services/a-rex/lrms/slurm/test/submit' /usr/bin/make basic-test memory-test count-test queue-test job-name-test cpu-wall-time-test rte-test config-options-test std-io-test user-env-test files-io-test basic-script.sh check_submit_script.sh submit-SLURM-job configure-SLURM-env.sh submit_common.sh lib/arc/arcconfig-parser command-simulator.sh make[9]: *** No rule to make target 'basic-script.sh'. Stop.

See full log here: https://source.coderefinery.org/nordugrid/arc/-/jobs/1516