Bug#759260: [summary] Bug#759260: removal of the Extra priority.

[Charles Plessy <plessy@debian.org>]

Control: reopen -1
Control: tag -1 + patch

[CCed everybody who contributed in #758234 and #759260, sorry if you
were not interested in that part of the discussion]

Hello again,

Here is a summary of the discussion in #759260 (cloned from #758234), regarding
the suppression of the Extra priority.  The purpose of the original proposition
was to ease the manual adjustment of higher priorities, but aside from that
goal, there was a broad agreement that the Extra priority is not really needed
anymore.

The submitted patch (https://bugs.debian.org/759260#62) deletes the whole
paragraph on the Extra priorities, as well as the requirement for pairs of
conflicting packages that at most one is above the lowest priority.  It was
seconded in https://bugs.debian.org/759260#67, and other messages in the
discussion are also going in the same direction
(https://bugs.debian.org/759260#47).  A second call for support or objections
was given on Oct 6: (https://bugs.debian.org/759260#131), and in the absence of
feedback, the bug was closed on  Oct 20 (https://bugs.debian.org/759260#136)
was closed.  I am reopening is because I think that we have actually reached
consensus for the change.

One of the potential uses of the Extra priority was to allow for co-installing
all packages down to the Optional priority.  However, this goal is not seem
realistic anymore given the current size of the Debian archive, and indeed, no
concrete example (that is, not just a though experiment or a single exploratory
attempt) of relying on this co-installability was given.

The Extra priority was also defended on the basis that it is useful for at
least transitional packages and detached debug
symbols(https://bugs.debian.org/759260#83).  However, these are better managed
with Sections instead of Priorities.  (https://bugs.debian.org/759260#108).

The Extra priority was also said to be potentially useful to see which packages
are safe to remove, or to search for them.  If Extra were removed, it would not
be possible anymore to define defaults for conflicting Optional packages.
However I am unsure that in that case there are real defaults in the same sense
that exim is default and postifx is not.

After reading the whole thread, I think that the objections against the removal
of the Extra priority have been adequately addressed, and the people who raised
them (mostly Ansgar and Matthias), while not supporting the change, are not
opposing it to the point of asking to block it.

Therefore, I second Gerrit's proposition.  Together with Jonathan's seconding, this
opens the way for a Policy change if Editors agree and of course if there is no
last-minute novel argument.

Have a nice day,

-- 
Charles Plessy
Debian Med packaging team,
http://www.debian.org/devel/debian-med
Tsurumi, Kanagawa, Japan