Re: transitive shared library dependencies and installation

[Bob Friesenhahn]

On Sun, 5 Jan 2020, address@hidden wrote:
> On the other hand, this overlinks the final binary:
>
> $ objdump -p .libs/translib | fgrep NEEDED
>  NEEDED               liba.so
>  NEEDED               libb.so
>  NEEDED               libc.so.6
>
> libb.so is unneeded here (but is present in the installed program as
> well).  Coincidentally, the most prominent search result
> https://wiki.mageia.org/en/Overlinking_issues_in_packaging mentions that
> "this is fixed using a patch from Debian" for libtool.
>
> What's your position on this?  Is overlinking a problem or not?  (It
> causes problems for distributions.)  Should everybody use --as-needed
> globally to combat it?  Something else entirely?

This has been the most common complaint (in the GNU Linux world) I 
have heard about libtool.  There is a choice of working reliably and 
portably (with possible over-linking) or relying on implicit library 
dependencies (which are definitely not portable), or failing as you 
have encountered.  A similar complaint is that libtool uses 
information in installed ".la" files in order to link with all 
libraries that the program/library is dependent on.  Due to this, GNU 
Linux distributions often patch out this capability, and they don't 
distribute ".la" files.

Unfortunately, --as-needed may not be 100% reliable since it only 
reliably detects direct dependence on library symbols, and not 
"transitive" dependence.

Bob
--
Bob Friesenhahn
address@hidden, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer,    http://www.GraphicsMagick.org/
Public Key,     http://www.simplesystems.org/users/bfriesen/public-key.txt