Nginx git error (http 502)

2015/03/04 20:04:06 [error] 19557#0: *391 upstream prematurely closed FastCGI stdout while reading response header from upstream, client: 95.175.3.2, server: test.com, request: "GET /git/testrepo/ HTTP/1.1", upstream: "fastcgi://unix:/var/run/fcgiwrap.socket:", host: "test.com"