Build from souce got error on centos7.2

when I Install GitLab Shell

this commond cannot use :
sudo -u git -H bundle exec rake gitlab:shell:install REDIS_URL=unix:/var/run/redis/redis.sock RAILS_ENV=production

HEAD is now at c615ca4 Bumped version to 2.7.2
Could not find rake-10.5.0 in any of the sources
Run bundle install to install missing gems.
Could not find rake-10.5.0 in any of the sources
Run bundle install to install missing gems.

but when I su - git and use commond bundle exec rake gitlab:shell:install REDIS_URL=unix:/var/run/redis/redis.sock RAILS_ENV=production
is OK.

Why?