I am trying to change the output of ares-package filename but it seems it doesn't work.

Looking as the help section, this should generate the file called foopkg_1.0.1.ipk:

ares-package APP_DIR -f -pn foopkg -pv 1.0.1

But i am keep getting the error: The specified path does not exist <foopkg>.
Am i doing something wrong?

My command is ares-package ./build -f -pn foopkg -pv 1.0.1.