Bug#218995: Patch for #218995
On Wed, Sep 26, 2012 at 03:50:52PM +0200, David Kalnischkies wrote:
>On Wed, Sep 19, 2012 at 1:55 PM, Steve McIntyre <steve@einval.com> wrote:
>> On Wed, Sep 19, 2012 at 01:40:39PM +0200, David Kalnischkies wrote:
>>>
>>>I think we will go with the attached patch, which prints a human-readable
>>>nearly debian-style compare operator. I say nearly as I want to highlight
>>>that - as is in other code paths - the dependency found in Packages:
>>>Depends: awesome (<< 2-1) | awesome (>> 3-1)
>>>will be printed as:
>>>Depends: awesome (< 2-1) | awesome (> 3-1)
>>>
>>>This is an interpretation difference, as older debian policies (now in
>>>§4.9.4 we reached the stage of denial: You must not use them) allowed
>>>the usage of '<' with the meaning of '<='. So be careful while parsing it
>>>that the right interpretation is used.
>>>The rest are one on one mappings.
>>
>> Hmmm. Could we stick with the same format as in Packages instead,
>> please? It's much less open to confusion that way... :-/ Other people
>> will end up reading logs from debian-cd, for example.
>
>Short version: Mhh.
>Okay - just for you now in wheezy. ;)
>For Jessie we will drop this difference for everyone.
>Updated patch attached.
Ummmm - where? :-)
>Novella version:
>'<' and '>' in Debian are long obsolete and dpkg-gencontrol and lintian
>warn (obsolete-relation-form-in-source) about their usage, so I guess it
>is more confusing for tools than for people (as the later will forget the minor
>detail they have read in the policy, tools usually don't forget that easily).
>
>Anyway, I walked through history a bit in a try to figure out why APT
>tries to establish it's own style here and it seems to originate from the
>"good old" times of "lets replace dpkg" and "lets work with 'aliens', too".
>("alien" seems to be rpm, but it is never mentioned explicitly and while
>an old apt-rpm fork exists which uses these abstraction levels it never
>caused support for "alien" to ever land in mainline so far…)
Right.
>Walking a bit through code tells me that this is actually the first time
>we use it in output which can be used by others. The old uses are only in
>debug code and in the broken dependency list message which is far from
>being parser friendly anyway. A quick grep in aptitude suggests similar
>usage patterns. And somehow I doubt that this style has that many users
>(if at all) out there given that it is not documented and far to similar
>to the usual debian-style you would usually expect to see here …
>
>Combining the two threads suggests that this is a perfect opportunity to
>change behavior here by dropping APT-style for Jessie before providing
>officially a command which will not allow us to do that in the future.
>And as I can't time-travel we will fake it (for apt-cache depends) until
>we make it (for all in DepIterator::CompType() ).
OK, cool.
I'll update the debian-cd code to use the new output style as soon as
I see the patch... :-)
--
Steve McIntyre, Cambridge, UK. steve@einval.com
"Managing a volunteer open source project is a lot like herding
kittens, except the kittens randomly appear and disappear because they
have day jobs." -- Matt Mackall
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