[gentoo-dev] Re: Subslots: should they be bumped like SONAME or on any ABI changes?

[Michael Palimaka <kensington@gentoo.org>]

On 06/15/2014 02:50 AM, Alexandre Rostovtsev wrote:
> On Sat, 2014-06-14 at 16:41 +0200, Michał Górny wrote:
>> Considering the libtool versioning, there are two kinds of library
>> bumps relevant to us:
>>
>> 1) when ABI is altered in backwards-compatible way (so old stuff is not
>> touched),
>>
>> 2) when ABI is altered in backwards-incompatible way.
> 
> The situation is more nuanced. I have also seen the following cases:
> 
> 3) a package provides multiple libraries or entry points, and only some
> of them have their ABI altered in a backwards-incompatible way.
> Examples: xorg-server changes ABI for video drivers, but not for input
> drivers; poppler changes ABI for libpoppler, but not libpoppler-glib.
It depends on the package, but with packages like poppler a consumer
should only use a sub-slot dependency operator if it's using the
unstable interface.

> 4) a package alters a "private" ABI which matters for a small number of
> closely-tied packages, but is transparent to normal users of the
> library. Example: glib and gobject-introspection.
Since the "normal" interface is stable I certainly hope no other
consumers are making use of that subslot.