error starting varnish

gistfile1.txt

 * Starting HTTP accelerator varnishd                                                      [fail] 
Message from VCC-compiler:
Backend host '":localhost:8080"' could not be resolved to an IP address:
	Servname not supported for ai_socktype
(Sorry if that error message is gibberish.)
(input Line 2 Pos 13)
    .host = ":localhost:8080";
------------#################-

In backend specification starting at:
(input Line 1 Pos 1)
backend default {
#######----------
Running VCC-compiler failed, exit 1
VCL compilation failed