Bug#539434: cupt and apt-get disagree on projected download and install size

reassign 539434 apt
retitle 539434 apt: does not report properly perform unit conversions
tags 539434 -moreinfo
thanks

On Fri, Jul 31, 2009 at 1:13 PM, Eugene V. Lyubimkin<jackyf.devel@xxxxxxxxx> 
wrote:
> > This may be a bug in apt-get or cupt, I'm not sure. But the same
> > command on both produces different predictions on the downloaded and
> > installed size of the same set of packages:
> >
> > The following 9 packages will be INSTALLED:
> >
> > iceweasel libmozjs1d libnspr4-0d libnss3-1d libstartup-notification0 
> > libxcb-atom1 libxcb-aux0 libxcb-event1 xulrunner-1.9
>
> Given the small differences, I cannot try to verify this on my system, so
> let's verify the result on yours.
>
> Let's do 'cupt show iceweasel libmozjs1d libnspr4-0d libnss3-1d
> libstartup-notification0 libxcb-atom1 libxcb-aux0 libxcb-event1 xulrunner-1.9
> | grep ize' and summarize sizes by hand (xcalc, bc -q etc.) to see which
> package manager is not right.

This looks like a bug in apt. Observe:

dmr@skynet:~$ echo "(+ $(apt-cache show iceweasel libmozjs1d libnspr4-0d libnss3-1d 
libstartup-notification0 libxcb-atom1 libxcb-aux0 libxcb-event1 xulrunner-1.9  | grep 
^Size | awk '{print $2}' | xargs))" | ypsilon -m
>
10418344

So apt itself agrees that the expected Size of these packages is 10418344 Bytes.

Now, the question is, should apt say there are 1024 bytes in a kilobyte, or 1000? Apt currently does the latter and truncates this to 10.4 MiB. I believe the former is more proper, and it should reconvert this to 9.94 MiB. 

Note that other UNIX tools, like "free", also follow the former convention like 
cupt.

Regards,
Daniel

--
Daniel Moerner <dmoerner@xxxxxxxxx>

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