make: g++ command not found error with makefile -

i'm writing makefile so:

lib_dir = $(shell pwd)/.linuxbrew/cellar/boost/1.62.0/  flags = -std=c++14  inc= -i$(lib_dir)include lib_path = -l$(lib_dir)lib lib = $(lib_dir)lib  libnames := filesystem-mt filesystem system-mt system  libs := $(foreach n,$(libnames),$(lib)libboost_$n.a $(lib)libboost_$n.dylib)  path = /some/path/  default:         g++ main.cpp $(flags) $(inc) $(lib_path) $(libs) -o assemble         ./assemble $(path)  clean:         rm assemble 

the problem is, once include variable 'lib_dir', complains g++ can't found. use help.

it's not lib_dir, rather path that's killing you. try commenting out line. (i'm assuming g++ not in /some/path/)