On Mon, Sep 22, 2014 at 08:02:19PM +0200, Guillem Jover wrote: > > If I tell a program to do something and the program can't do that, > > that's an error. In this case, however, I'm merely asking dpkg what he > > would do, so the messages are not of the "sorry, I can't do that" type, > > but instead "Look, this is what I would do". > > Could you provide an actual example of the problematic output to know > what do you think is misbehaving? Because if I do this on say fbset, I > get on stdout: > > ,--- > (Reading database ... 219138 files and directories currently installed.) > Would remove or purge fbset (2.1-28) ... > `--- > > but if I do this on dpkg I get something like this on stderr: > > ,--- > dpkg: error processing package dpkg (--purge): > this is an essential package; it should not be removed > Errors were encountered while processing: > dpkg > `--- > > Is stuff like that what you perceive as an issue?
Yes. I think both cases should go to stdout, not only the first one. In my case, I was trying to determine why apt-get wanted to remove stellarium today when doing "apt-get dist-upgrade". There was a message saying The following packages were automatically installed and are no longer required: libqt5concurrent5 libqt5core5a libqt5dbus5 libqt5gui5 libqt5network5 libqt5opengl5 libqt5printsupport5 libqt5qml5 libqt5quick5 libqt5script5 libqt5sql5 libqt5widgets5 libxcb-render-util0 libxcb-sync1 libxcb-xkb1 libxkbcommon-x11-0 stellarium-data so I copied and pasted the list above into a file called "AR" and then tried to see if I could really remove any of them individually: for a in `cat AR`; do dpkg --no-act --purge $a; done | less I naively thought that no 2>%1 would be needed here because of the --no-act option, but I was wrong. > For me the only difference between the two is that it's acting the same > except that it does not perform any actual modification (as documented > in the man page), so at least the above two examples make perfect sense > to me. :) It is certainly *not* the only difference: In your first example, dpkg seems to realize that it is performing a simulation and the wording is clearly different because of the --no-act option, as it says: *Would* remove or purge fbset To be consistent, dpkg could similarly say "Would not remove/purge package foo because it is essential". without making the alarms sound as if it were the real thing. This is somehow a matter of principles: If a program does what you ask it to do, then there is no error. If dpkg was actually *unable* to tell me what would happen, that would be indeed an error and using stderr would be completely justified, but in this case dpkg does what I ask it to do (i.e. tell me what would happen). Thanks. -- To UNSUBSCRIBE, email to [email protected] with a subject of "unsubscribe". Trouble? Contact [email protected]
