Portage Profiles
Classic Initialization
Classic profile initialization has been documented in this GitHub commit. The following is an overview of the code comments:
A. Find profile directory/symlink
- Look for a profile directory/symlink at /etc/make.profile, if one exists, use this as the main profile directory.
- If /etc/make.profile doesn't exist, use /etc/portage/make.profile as a back-up location if it also exists.
- If neither location exists, then a main profile directory doesn't exist.
B. Initialize Cascading Profiles
Using the main profile directory/symlink found above, the LocationsManager._addProfile() recursive function will be called that will create a list of all cascading profiles. This works by looking for a parent file in the profile directory. If this file exists, then each line is treated as a relative path and used to modify the path to the current profile, pointing to a "parent" profile that this particular profile modifies. There can be one than more parent, one per line. The first line in the parent file is the highest-priority parent.
Once this list is created, the code checks to see if /etc/portage/profile directory exists. If it does, it is tacked at the end of the cascading profile list, meaning that it is evaluated last and this user-defined profile has the ability to modify any of the cascading profile settings.
