Re: Package Version Numbers
"Boyd Stephen Smith Jr." <bss@iguanasuicide.net> wrote:
>In <[🔎] 47pt7511s56vq779jtfp2ap0059a8m4et7@4ax.com>, Jeff Grossman wrote:
>>mail:~# apt-cache policy php5
>>php5:
>> Installed: 5.2.6.dfsg.1-1+lenny3+custom1
>> Candidate: 5.2.9.dfsg.1-4
>> Version table:
>> 5.2.10.dfsg.1-2 0
>> 200 http://ftp.us.debian.org unstable/main Packages
>> 5.2.9.dfsg.1-4 0
>> 300 http://ftp.us.debian.org testing/main Packages
>> *** 5.2.6.dfsg.1-1+lenny3+custom1 0
>> 100 /var/lib/dpkg/status
>> 5.2.6.dfsg.1-1+lenny3 0
>> 500 http://ftp.us.debian.org lenny/main Packages
>> 500 http://security.debian.org lenny/updates/main Packages
>>
>>What I don't understand is how come the candidate is 5.2.9 when that
>>has a pinning of 300, clearly lower than 5.2.6.
>
>Because apt refuses to downgrade unless a specific version is specified (or
>the priority is > 1000). Downgrades aren't supportable; they may work most
>of the time but if they don't they are virtually impossible to fix.
>
>So, when apt is considering which version to install it starts with:
> 5.2.10.dfsg.1-2 200
> 5.2.9.dfsg.1-4 300
> 5.2.6.dfsg.1-1+lenny3+custom1 100
> 5.2.6.dfsg.1-1+lenny3 500
>
>Now, it throws away anything with a priority of less than 0, but that
>doesn't change anything. Then, it throws away anything if a version of less
>tham 5.2.6.ddfsg.1-1+lenny3+custom1 (current version) and a priority of less
>than 1000. This leaves:
> 5.2.10.dfsg.1-2 200
> 5.2.9.dfsg.1-4 300
> 5.2.6.dfsg.1-1+lenny3+custom1 100
>
>At this point, it chooses the one(s) with the highest priority:
> 5.2.9.dfsg.1-4 300
>
>Since there's only one version left, it is the candidate. If there were
>multiple versions left it would choose the one with the highest version.
>
>>Did I use the correct naming convention when I setup my custom version
>>of PHP?
>
>Yes, but running a mixed system (or even a not-mixed system with testing and
>unstable in your sources.list) requires a but more effort than running pure
>stable.
Thank you for this valuable information. I was not aware of how apt
or aptitude figured out what to upgrade. I guess I will pin my custom
version of php5 to a priority of 1000 so it does not bother me with
trying to upgrade anymore.
Jeff
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