Issue with passing environment variable to make file

Question

In my make file I have 2 parameters defined as below with default values. PARAM1?= 2 PARAM2?= 11 I am using these parameters in my target cpp_run.

cpp_run:
    ./dig_vr_App $(PARAM1) $(PARAM2) |& tee run_Cpp.log

However if I pass the parameters from the command line for example

make cpp_run PARAM1=102 PARAM2=0

the make file still picks up the default values, ie, 2 and 11 (from the log file run_cpp.log). I followed other posts which says use PARAM1=num1 and PARAM2=num2 in the command line as shown above but it doesn't work.

Answer 1

As I said in my comments, you are not telling us something. I created this test:

$ cat Makefile
PARAM1 ?= 2
PARAM2 ?= 11

cpp_run:
         @echo ./dig_vr_App $(PARAM1) $(PARAM2)

and it works exactly how I'd expect:

$ make --version | head -n2
GNU Make 4.3
Built for x86_64-pc-linux-gnu

$ make cpp_run
./dig_vr_App 2 11

$ make cpp_run PARAM1=102 PARAM2=0
./dig_vr_App 102 0

So there's something about your environment or makefile that you haven't explained to us.