Re: Bug#904019: ITP: libxcrypt -- Extended crypt library for DES, MD5, Blowfish and others

[Guillem Jover <guillem@debian.org>]

On Fri, 2018-07-20 at 02:18:51 +0200, Marco d'Itri wrote:
> On Jul 18, Marco d'Itri <md@linux.it> wrote:
> > Some day it may replace crypt(3), currently provided by glibc:
> > https://fedoraproject.org/wiki/Changes/Replace_glibc_libcrypt_with_libxcrypt

> I tried creating a package which would divert libc's libcrypt, but it 
> appears to be much harder than I thought.
> 
> Installing it would looke like:
> 
> 1) libcrypt1.preinst diverts glibc's libcrypt.so.1
> 2) dpkg does things
> 3) dpkg installs libxcrypt's libcrypt.so.1
> 4) dpkg does more things
> 5) libcrypt1.postinst runs/triggers ldconfig
> 
> And this means that perl (a libcrypt dependency) would be broken between 
> 1 and 5 (or maybe 1 and 3): is this ever going to work?

Given that this new package is going to replace a part of glibc, it
will need to behave as if it was part of the pseudo-Essential package
set. When it comes to the diversion that means it needs to be added
*without* the rename, so that we always have the libcrypt.so.1 present.

But otherwise why would it be broken?

> But even if this worked correctly, glibc installs a libcrypt-N.NN.so, 
> whose exact name I expect changes among different releases.

This one is tied to the major.minor glibc version, so I think you
should just ignore it. I'd expect at most glibc itself to perhaps rely
on it, anything else using it would not be very sane IMO.

Thanks,
Guillem