Resolution: Cannot Reproduce
The Puppet agent doesn't correctly determine when a yum group has been installed because the grep is case sensitive:
Debug: Exec[Group Install Development Tools](provider=posix): Executing check 'yum grouplist 'Development Tools' | grep '^Installed Groups''
Debug: Executing 'yum grouplist 'Development Tools' | grep '^Installed Groups''
Notice: /Stage[main]/Development::Install/Yum::Groupinstall[Development Tools]/Exec[Group Install Development Tools]/returns: current_value notrun, should be 0 (noop)
- yum grouplist 'Development Tools'
Loaded plugins: fastestmirror, priorities
Loading mirror speeds from cached hostfile
49 packages excluded due to repository priority protections
Notice that the agent is grepping on '^Installed Groups' but the output uses a lower case 'g' for groups.