Re: [Gábor Gombás] Bug#564566: libkadm5clnt7: SONAME conflict with Heimdal

[Jeffrey Hutzelman]

--On Monday, January 11, 2010 04:56:30 PM -0500 Sam Hartman 
<hartmans at mit.edu> wrote:

>>>>>> "Jeffrey" == Jeffrey Hutzelman <jhutz at cmu.edu> writes:
>
>     Jeffrey> Of course, if the symbol versions also don't match, symbol
>     Jeffrey> resolution will just fail and things will not work at all.
>     Jeffrey> Symbol versioning, especially of the rich variety provided
>     Jeffrey> by glibc, can be used here to prevent the wrong thing from
>     Jeffrey> happening, but it can't make the right thing happen.
> No, that's not true.
> If glibc finds krb5_init_context at krb5_3_mit and
>  krb5_init_context at krb5_17_heimdal and the code was looking
>  for krb5_init_context at krb5_3_mit, the right thing will
>  happen regardless of which is found first.

Yes, that's true.  What symbol versioning can't do is cause the correct 
library to be loaded in the first place.  The only sane way to do that is 
to not have two ABI-incompatible libraries with the same soname.  When such 
a situation arises, the only sane thing to do is fix it.