Library naming conventions & confusions

[sling-shot]

I have a difficulty in following some of our package naming conventions when it comes to libraries.
Recently, I am confused about libtorrent-rasterbar.
The final built library package is named libtorrent-rasterbarn where n is the major number.
However this number is not part of the version number but is attached to the library name.
But the devel package is plainly named libtorrent-rasterbar-devel
So an upgrade of libtorrent-rasterbar will cause upgrade of the devel-package but 2 libtorrent-rasterbar packages named n and m.

Probably this is done to facilitate keeping multiple versions of the same library.

Now when a package needs libtorrent-rasterbar to build, it cannot be built with libtorrent-rasterbar but with libtorrent-rasterbarn. However if libtorrent-rasterbarn gets updated and older version removed it will cause that package fail to install because that library is lacking.

Is that the reason why we have some 3 - 4 different packages of the same library in our repository?

How should I create the .spec file for the library / package in a situation where the repo has an older version of the library but a new package needs a newer version of the same library?

[TerryN]

The -devel package should represent the latest stable version  (i.e the one we are currently building against).

You are correct that the major number (the ABI version) is added to the final library name so that older versions can be kept in the repo to cater for dependent packages that haven't been rebuilt against the new ABI version (ideally they all should be rebuilt and the old library can then be removed to stop the repo getting cluttered with old versions).  Without that difference in package name apt/synaptic would remove the old library and replace it with the new during an update resulting in broken packages.  All new packages should be being built against the latest stable ABI version which is why the -devel package does not generally have the major number added to the name.

You don't need to do anything to the SPEC file.  You specify libtorrent-rasterbar-devel in the Buildrequires and that will install (currently) libtorrent-raterbar-devel-0.15.8-1 (which is for ABI version 6) which means you are building against the currently supported version.  If a package won't (or can't be patched to) build against the current version it is probably not worth having  

Terry.

[sling-shot]

Hmmm... that seems to clear things up. Or am I hallucinating ? Whooops...

[gseaman]

If you have to build against an older library, you can downgrade the -devel file to the one that matches the desired library version, and then build your package against it. This should be rare, though.

Galen