I have perfomed git clone https://github.com/gitlabhq/gitlabhq.git and executed bundle install.Then I executed bundle exec rake db:migrate in Ubuntu.
I got this warning
~/Siva/Clone/gitlabhq$ bundle exec rake db:migrate
WARNING: This version of GitLab depends on gitlab-shell 2.6.3, but you're running Unknown. Please update gitlab-shell.
20141121133009 AddTimestampsToMembers: migrating execute("UPDATE members SET created_at = now() WHERE created_at is NULL")
rake aborted!
StandardError: An error has occurred, this and all later migrations canceled:
SQLite3::SQLException: no such function: now: UPDATE members SET created_at = now() WHERE created_at is NULL/home/siva/Siva/Clone/gitlabhq/db/migrate/20141121133009_add_timestamps_to_members.rb:8:in up'
ActiveRecord::StatementInvalid: SQLite3::SQLException: no such function: now: UPDATE members SET created_at = now() WHERE created_at is NULL
/home/siva/Siva/Clone/gitlabhq/db/migrate/20141121133009_add_timestamps_to_members.rb:8:in
up'