I'm going to take a wild guess that the issue is because vivid's nginx-common.postinst has this line:
invoke-rc.d nginx start || exit $?
Which will make postinst fail if nginx fails to start for the first time.
15.04:
http://bazaar.launchpad.net/~ubuntu-branches/ubuntu/vivid/nginx/vivid/view/head:/debian/nginx-core.postinst
14.04 did not have this behaviour:
http://bazaar.launchpad.net/~ubuntu-branches/ubuntu/trusty/nginx/trusty/view/head:/debian/nginx-common.postinst
I'm going to take a wild guess that the issue is because vivid's nginx-common. postinst has this line:
invoke-rc.d nginx start || exit $?
Which will make postinst fail if nginx fails to start for the first time.
15.04:
http:// bazaar. launchpad. net/~ubuntu- branches/ ubuntu/ vivid/nginx/ vivid/view/ head:/debian/ nginx-core. postinst
14.04 did not have this behaviour:
http:// bazaar. launchpad. net/~ubuntu- branches/ ubuntu/ trusty/ nginx/trusty/ view/head: /debian/ nginx-common. postinst