When trying to integrate Mingle with Perforce , it just returning a “Repository is empty” message.
Please locate the P4 Ticket created on your machine, this ticket will have a "GUID" value. Copy this GUID value and paste it in the "Password" field in Mingle on the perforce configuration page.
Perforce client programs store tickets in the file specified by the P4TICKETS environment variable. If this variable is not set, tickets are stored in %USERPROFILE%\p4tickets.txt on Windows, and in $HOME/.p4tickets on UNIX and other operating systems.