[RFC/HEADSUP] portmaster default -w (preserve shared libraries)

[Warren Block]

On Tue, 11 Dec 2012, Bryan Drewery wrote:

> (As maintainer) I'm proposing to make -w the default for portmaster.
> This will preserve old shared libraries when upgrading. This helps 2 things:
>
> 1. Prevents a broken system during upgrades
> 2. Prevents a broken system after upgrading for ports that did not get a
> PORTREVISION bump from a shared library update.
>
> You have certainly ran into this problem with large library updates such
> as png, pcre, openssl, etc.
>
> Portupgrade has always done this as default, and I have never seen any
> problems arise from it. It also cleans up prevents duplicated library
> versions. If portmaster is not already doing this, I will ensure it does.
>
> You could then use pkg_libchk to rebuild any lingering ports if you
> wanted to ensure your system was using the latest. Then cleanout the
> preserved shared library.
>
> Of course there will be a way to stick to the old default of not
> preserving the libraries.
>
> Someone may consider this a POLA violation, but I consider that a broken
> system from missing libraries and PORTREVISION bumps is more of a POLA
> violation.

The -w behavior by default seems reasonable.  When implemented, it 
should be mentioned in UPDATING.  pkg_libchk should also be mentioned as 
a way of finding installed applications that are depending on old 
libraries in /usr/local/lib/compat/pkg.