[Fedora-packaging] Packaging guidelines for Emacsen add-on packages

[Ville Skyttä]

On Wednesday 30 May 2007, Tom "spot" Callaway wrote:
> On Wed, 2007-05-30 at 09:47 +0300, Ville Skyttä wrote:
> > On Wednesday 30 May 2007, Tom "spot" Callaway wrote:
>
> > > Good lord. No. Thou shalt not query rpm inside rpm.
> >
> > Disagreed, when done carefully.
>
> There is no careful way to do it. It is not safe, it is not predictable,
> it is not reproducable.

My experience says otherwise, so would you care to elaborate and back each of 
those claims up with some concrete examples, in particular explaining in 
which way querying rpm is less $something than querying emacs or xemacs in 
that case?

> emacs --version | head -n1 | sed -e 's/[^0-9.]//g'
> xemacs -V -no-site-file | cut -d " " -f 2
>
> Not that hard.

And both of those have a fundamental issue that they're disconnect with what 
we need - the rpm *package* version; unless of course emacs/xemacs add a 
versioned Provides or something like the httpd-mmn mechanism in the httpd 
package that aligns better with what can be retrieved from querying them or 
something non-rpm.

They also lack the possibility of querying Epochs (not needed currently in the 
*emacs case, just mentioning because you generalized all rpm querying as bad), 
and the output of those commands need to be watched and verified between 
upstream revisions (which sooner or later results in a mess of tweaks or 
inability to support all versions which would be useful), and user init files 
possibly suppressed more than in the above, etc.  BTW,  the xemacs version 
above produces wrong results; we want eg. 21.5.27, not 21.5.