nova installation problem

/home/stack/devstack/local.sh: line 71: /opt/stack/nova/bin/nova-manage: No such file or directory 2015-03-26 12:25:30.369 | /home/stack/devstack/local.sh: line 71: /opt/stack/nova/bin/nova-manage: No such file or directory 2015-03-26 12:25:30.369 | /home/stack/devstack/local.sh: line 71: /opt/stack/nova/bin/nova-manage: No such file or directory 2015-03-26 12:25:30.370 | /home/stack/devstack/local.sh: line 71: /opt/stack/nova/bin/nova-manage: No such file or directory 2015-03-26 12:25:30.371 | /home/stack/devstack/local.sh: line 71: /opt/stack/nova/bin/nova-manage: No such file or directory 2015-03-26 12:25:30.372 | /home/stack/devstack/local.sh: line 71: /opt/stack/nova/bin/nova-manage: No such file or directory 2015-03-26 12:25:30.373 | /home/stack/devstack/local.sh: line 71: /opt/stack/nova/bin/nova-manage: No such file or directory 2015-03-26 12:25:30.374 | /home/stack/devstack/local.sh: line 71: /opt/stack/nova/bin/nova-manage: No such file or directory 2015-03-26 12:25:30.374 | /home/stack/devstack/local.sh: line 71: /opt/stack/nova/bin/nova-manage: No such file or directory 2015-03-26 12:25:30.376 | ++ err_trap 2015-03-26 12:25:30.377 | ++ local r=127 2015-03-26 12:25:30.378 | stack.sh failed: full log in /opt/stack/logs/stack.sh.log.2015-03-26-173854 2015-03-26 12:25:30.379 | Error on exit help me....