Apt.Pref
for details on the apt_preferences format : man apt_preferences
type pin_t =
| Release of (string * string) list
| Origin of string
| Version of string
type package_t =
| Package of string
| Star
type pin_priority_t = int
type apt_preferences = {
package : package_t;
pin : pin_t;
pin_priority : pin_priority_t;
}