Doing everything as user stack like the documentation recommends, ./stack.sh on ubuntu 14.04 fails with these errors. Passwordless sudo does work and the previous parts of the install that require root access work, it seems to be trying to do root level things as the stack user here.

+ configure_keystone
+ sudo install -d -o stack /etc/keystone
+ [[ /etc/keystone != \/\o\p\t\/\s\t\a\c\k\/\k\e\y\s\t\o\n\e\/\e\t\c ]]
+ install -m 600 /opt/stack/keystone/etc/keystone.conf.sample /etc/keystone/keystone.conf
+ cp -p /opt/stack/keystone/etc/policy.json /etc/keystone
cp: cannot create regular file '/etc/keystone/policy.json': Permission denied
+ exit_trap
+ local r=1
++ jobs -p
+ jobs=
+ [[ -n '' ]]
+ kill_spinner
+ '[' '!' -z '' ']'
+ [[ 1 -ne 0 ]]
+ echo 'Error on exit'
Error on exit
+ [[ -z /opt/stack/logs ]]
+ /opt/stack/devstack/tools/worlddump.py -d /opt/stack/logs
World dumping... see /opt/stack/logs/worlddump-2015-04-14-151400.txt for details
df: '/run/user/1000/gvfs': Permission denied
+ exit 1