prepare (1/3): 
finished

make (2/3): 
make: Circular main <- main dependency dropped.
g++ -g -Wall -O2 -o main main
g++: error: main: No such file or directory
g++: fatal error: no input files
compilation terminated.
Makefile:20: recipe for target 'main' failed
make: *** [main] Error 1

build failed