My fuzzylite is located at ~/fuzzylite-6.0/fuzzylite. I cd to the directory of ObstacleAvoidance.cpp (in ~/ObstacleAvoidance) and enter the following command: g++ ObstacleAvoidance.cpp -o ObstacleAvoidance -l/fuzzylite-6.0/fuzzylite -L/fuzzylite-6.0/fuzzylite/release/bin -lfuzzylite-static --std=c++11
your problem is that the paths are wrong. In particular, -l/fuzzylite-6.0/fuzzylite is pointing to root /, and same as -L/fuzzylite-6.0/fuzzylite/release/bin. They should be -l/home/yourname/fuzzylite-6.0/fuzzylite -L/home/yourname/fuzzylite-6.0/fuzzylite/release/bin`.
In any case, make sure that both paths are accessible from where you run. Just executing the path will tell you whether it is a directory or not in terminal:
-bash: /fuzzylite-6.0/fuzzylite: No such file or directory
-bash: /Users/juan/dev/fuzzylite-6.0/: is a directory