[gentoo-dev] Avoiding rebuilds (was: don't rely on dynamic deps)

[Ulrich Mueller]

>>>>> On Sun, 27 Jul 2014, Martin Vaeth wrote:

> Kent Fredric <kentfredric@×××××.com> wrote:
>> -r1.1 weirdness feels like it may cause more problems than it solves.

> So far, nobody pointed out any problem which would be caused by -r1.1.
> Which is not surprising, since the idea is that -r1.1 cannot be
> distinguished from -r2:
> It is only a hint to the PM that he *may* shortcut certain phases when
> updating from -r1.

I wonder if it wouldn't be saner to leave our revision syntax
untouched.

Instead, one could introduce a variable INSTALL_VERSION that would
default to ${PVR} but could be set to the version of a previous ebuild
instead. The PM could compare it against INSTALL_VERSION in the VDB
and skip build and installation if versions match.

Advantages:
- Support for the variable could be optional. PMs not supporting it
  would do a regular revbump instead.
- One could even imagine USE-conditional syntax for the variable.

Ulrich