No rule to make target '-lm', needed by 'cubic'.

[charmoniumQ]

$ make --debug --directory=src/cubic
...
 File 'all' does not exist.
   File 'all-am' does not exist.
     File 'cubic' does not exist.
       File '-lm' does not exist.
      Must remake target '-lm'.
make: *** No rule to make target '-lm', needed by 'cubic'.  Stop.

Why can make not find -lm?

I saw something related to VPATH in this issue?