Re: RFC: relaxation of debian-emacs-policy dependency requirements

[Agustin Martin <agmartin@debian.org>]

On Tue, Jul 06, 2010 at 10:54:33PM -0500, Rob Browning wrote:
> Agustin Martin <agmartin@debian.org> writes:
> 
> > On Tue, Jul 06, 2010 at 11:51:06AM +0100, Ian Jackson wrote:
> 
> >> Why should a package which happens to also ship some elisp need to
> >> depend on any Emacs package at all ?  What will go wrong if the
> >> package is installed without any Emacs ?
> >
> > Agreed.
> >
> > lisp stuff in a package whose main use is not Emacs should be used if
> > an emacsen package is installed and ignored otherwise. There is nothing wrong
> > with that. Even if /var/lib/emacsen-common/installed-flavors was not
> > originally designed for that, seems a good way to know if emacsen-common is
> > configured, so a prerm snippet like
> >
> > if [ -x /usr/lib/emacsen-common/emacs-package-remove ] && 
> >    [ -e /var/lib/emacsen-common/installed-flavors ]; then
> >     /usr/lib/emacsen-common/emacs-package-remove #PACKAGE#
> > fi
> 
> I'd rather not handle it this way.  If we do relax the policy
> requirement, I'd rather abstract this a bit more, so that add-on
> packages don't directly depend on a detail of the current
> implementation, and commit emacsen-common to the maintenance of
> installed-flavors indefinitely.

We can alway use dpkg for this, just that using an ad-hoc flag set by 
emacsen-common is faster. Ian surely knows better ways for checking for 
emacsen-common status, but a prerm snippet like 

EC_READY=`dpkg --status emacsen-common 2> /dev/null | grep '^Status: .* installed$'`
if [ -x /usr/lib/emacsen-common/emacs-package-remove ] && [ "$EC_READY" ]; then
      /usr/lib/emacsen-common/emacs-package-remove #PACKAGE#
fi

should work. Actually if $EC_READY above is set, 
'/usr/lib/emacsen-common/emacs-package-remove' should already be available
and executable, otherwise is a bug, so just using

EC_READY=`dpkg --status emacsen-common 2> /dev/null | grep '^Status: .* installed$'`
if [ "$EC_READY" ]; then   
    /usr/lib/emacsen-common/emacs-package-remove #PACKAGE# 
fi

may be enough. 

-- 
Agustin