mysterious cloud haskell error

gistfile1.txt

darryl-mcadamss-macbook-pro:test-project darryl$ stack exec new-template-exe slave localhost 8080 & stack exec new-template-exe slave localhost 8081 & stack exec new-template-exe master localhost 8082
[3] 4928
[4] 4929
new-template-exe: bind: resource busy (Address already in use)
new-template-exe: bind: resource busy (Address already in use)
Slaves: [nid://localhost:8080:0,nid://localhost:8081:0]
[1]   Done                    stack exec new-template-exe slave localhost 8080
[2]   Done                    stack exec new-template-exe slave localhost 8081
[3]-  Exit 1                  stack exec new-template-exe slave localhost 8080
[4]+  Exit 1                  stack exec new-template-exe slave localhost 8081