$ make --debug=a,b V=1
...
 Considering target file `depends/hal/hal_lib.d'.
  File `depends/hal/hal_lib.d' does not exist.
   Pruning file `hal/hal_lib.c'.
  Finished prerequisites of target file `depends/hal/hal_lib.d'.
 Must remake target `depends/hal/hal_lib.d'.
Putting child 0x08c7ed70 (depends/hal/hal_lib.d) PID 26064 on the chain.
Live child 0x08c7ed70 (depends/hal/hal_lib.d) PID 26064
Reaping winning child 0x08c7ed70 PID 26064
Live child 0x08c7ed70 (depends/hal/hal_lib.d) PID 26065
Depending hal/hal_lib.c
Reaping winning child 0x08c7ed70 PID 26065
gcc -MM -MG -MT "depends/hal/hal_lib.d objects/hal/hal_lib.o" -I. -Ilibnml/linklist -Ilibnml/cms -Ilibnml/rcs -Ilibnml/inifile -Ilibnml/os_intf -Ilibnml/nml -Ilibnml/buffer -Ilibnml/posemath -Irtapi -Ihal -Iemc/nml_intf -Iemc/kinematics -Iemc/motion -Iemc/ini -Iemc/rs274ngc -Iemc/pythonplugin -I/usr/local/jepler/src/linuxcnc-master/src/include -I/usr/include/python2.6 -Os -g -Wall -DULAPI  -Wdeclaration-after-statement  -fPIC hal/hal_lib.c -o depends/hal/hal_lib.d.tmp && mv -f "depends/hal/hal_lib.d".tmp "depends/hal/hal_lib.d"
Live child 0x08c7ed70 (depends/hal/hal_lib.d) PID 26066
Reaping winning child 0x08c7ed70 PID 26066
Removing child 0x08c7ed70 PID 26066 from chain.
 Successfully remade target file `depends/hal/hal_lib.d'.
...