Some background: I'm using Debian 7 as my main environment, and I want to tell my system that I have
glibc = 2.15 in addition to the environment's required
glibc = 2.13 for the purposes of using some more recent applications.
I got the glibc from the various tutorials on the web for installing eg.: Steam. It is unpacked in
/usr/local/lib/libc6-2.15 and I've tested it with some applications such as Pidgin 2.10, Boinc 7 and Stellarium, it's working well (so far, I do expect it to eventually fail gracefully). Since it'd be much better if I could install those applications from packaged sources as well (both clang and Boinc are in testing for example), I'd like to tell my system via a virtual package that I do, in fact, have a glibc 2.15 available.
Of course I know about
equivs as a tool to create virtual packages for stuff that one does not have installed from repositories, but I have found no good documentation so far on how to use
equivs to create a virtual package that can update an already installed package, ideally without breaking.
I first tried the obvious:
Package: libc6 Version: 2.15-1
And dpkg-installed the generated package, with the expected result that it uninstalled the already present
libc to update and left the system in an unusable state. (Of course, I tried this in a VM). I've also tried
Version: >= 2.13
Without any good results.
I tried to look for a way of using Provides or Enhances by creating a package of a different name
Package: local-libc6 Version: 2.15 # Either this: Provides: libc6 # Or this: Enhances: libc6 (< 2.15)
But so far I have had no success in getting
equivs to create an installable package (aptitude complains about an invalid Provides or Enhances), or even to create a package at all.
Of course, the idea is to create a virtual package for
libc that won't uninstall the already installed one, and merely "provides" the new version. But I've found the documentation horribly lacking in that respect so far (and I really don't want to have to delve deep and become lost into the DPKG Encyclopedia; usually I have the disposition and time to do such tasks, but these days my focus is needed elsewhere).
So, I guess the base question is: can I use equivs to create an update for a package without uninstalling the original, or achieve something to that effect? What general cares do I need to exercise when specifying versions to