Missing dependencies means parallel build fails

Non-parallel builds are successful:

$ make
[ ... ]
### Built project successfully!!!###

But in parallel builds the lack of dependencies means the build will fail:

$ make -j
Building sub-component at val
gcc -DBASE_PROTOCOL -static -DVERBOSE_LEVEL=3  -Wall -Werror -DTARGET_ -I/home/ross/Mess/scmi-tests/val/include -I/home/ross/Mess/scmi-tests/test_pool/base/include -I/home/ross/Mess/scmi-tests/val/include -I/home/ross/Mess/scmi-tests/platform//include -c val_base.c -o /home/ross/Mess/scmi-tests/val_output/val_base.o
[ ... ]
a - /home/ross/Mess/scmi-tests/val_output/val_clock.o
a - /home/ross/Mess/scmi-tests/val_output/val_power_domain.o
a - /home/ross/Mess/scmi-tests/val_output/val_reset.o
a - /home/ross/Mess/scmi-tests/val_output/val_sensor.o
a - /home/ross/Mess/scmi-tests/val_output/val_system_power.o
ar: /home/ross/Mess/scmi-tests/test_output/*.o: No such file or directory
make: *** [Makefile:125: scmi_test] Error 1

ar is running before the compiler has finished.