[Aptitude-devel] Bug#385631: aptitude: Doesn't offer sensible solution upon conflict

Wed Jan 9 00:17:30 UTC 2013

Control: retitle -1 aptitude: Should show actions on packages on the commandline when showing resolver solutions
Control: severity -1 wishlist

Hi Wolf,

Wolf Wiegand wrote:
> > > backport:/home/wolf# aptitude -o 'aptitude::auto-install=false' install
> > > postfix
> > > Reading package lists... Done
> > > Building dependency tree... Done
> > > Reading extended state information       
> > > Initializing package states... Done
> > > Reading task descriptions... Done  
> > > Building tag database... Done    
> > > The following packages are BROKEN:
> > >   exim4-config exim4-daemon-light postfix 
> > > The following packages are RECOMMENDED but will NOT be installed:
> > >   resolvconf 
> > > 0 packages upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
> > > Need to get 949kB of archives. After unpacking 2265kB will be used.
> > > The following packages have unmet dependencies:
> > >   exim4-config: Conflicts: postfix but 2.2.10-2 is to be installed.
> > >   postfix: Depends: ssl-cert but it is not installable
> > >            Conflicts: mail-transport-agent which is a virtual package.
> > >   exim4-daemon-light: Conflicts: mail-transport-agent which is a virtual
> > > package.
> > > Resolving dependencies...
> > > The following actions will resolve these dependencies:
> > > 
> > > Remove the following packages:
> > > exim4
> > > exim4-base
> > > exim4-config
> > > exim4-daemon-light
> > > 
> > > Install the following packages:
> > > openssl [0.9.8b-2 (testing)]
> > > resolvconf [1.36 (testing)]
> > > ssl-cert [1.0.13 (testing)]
> > > 
> > > Score is -1569
> > 
> >   ...postfix will still be installed in this solution...
> 
> Indeed. Well, this bug should probably be retitled as enhancement bug.
> This question came up on debian-user-german at l.d.o, and besides me there
> were at least two other people failing to see that this solution will
> lead to postfix being installed.

This seems still the case in Squeeze:

root at acromantula-domu1:~# aptitude install postfix
The following NEW packages will be installed:
  file{a} libexpat1{a} libmagic1{a} libsasl2-2{a} libsasl2-modules{a} 
  mime-support{a} openssl{a} postfix{b} python{a} python-minimal{a} 
  python2.6{a} python2.6-minimal{a} ssl-cert{a} 
0 packages upgraded, 13 newly installed, 0 to remove and 0 not upgraded.
Need to get 7366 kB of archives. After unpacking 25.2 MB will be used.
The following packages have unmet dependencies:
  postfix: Conflicts: mail-transport-agent which is a virtual package.
  exim4-daemon-light: Conflicts: mail-transport-agent which is a virtual package.
  exim4-config: Conflicts: postfix but 2.7.1-1+squeeze1 is to be installed.
The following actions will resolve these dependencies:

     Remove the following packages:
1)     exim4-base                  
2)     exim4-config                
3)     exim4-daemon-light          

Accept this solution? [Y/n/q/?] 

Although it might be more obvious in this case as the proper solution
is chosen first.

> Is there a way, so that in the above
> situation, the following is written out?
> 
> | The following actions will resolve these dependencies:
> | 
> | Remove the following packages:
> | exim4
> | exim4-base
> | exim4-config
> | exim4-daemon-light
> | 
> | Install the following packages:
> | openssl [0.9.8b-2 (testing)]
> | resolvconf [1.36 (testing)]
> | ssl-cert [1.0.13 (testing)]
> | postfix [....... (testing)]      <--- added this line
> | 
> | Score is -1569
> 
> I think this would be really helpful, but I know too little about
> aptitude's internals to say if this is possible.

Maybe this helps already a little bit:

Accept this solution? [Y/n/q/?] ?
The following commands are available:
[...]
  o: toggle between the contents of the solution and an explanation of the
     solution
[...]
Accept this solution? [Y/n/q/?] o
     postfix conflicts with mail-transport-agent                    
1)    -> Removing exim4-daemon-light                                

     exim4-config conflicts with postfix                            
2)    -> Removing exim4-config                                      

     exim4-base depends upon exim4-config (>= 4.30) | exim4-config-2
3)    -> Removing exim4-base                                        

Accept this solution? [Y/n/q/?] o
     Remove the following packages:
1)     exim4-base                  
2)     exim4-config                
3)     exim4-daemon-light          

Accept this solution? [Y/n/q/?]

Another variant would be using the -D option:

# aptitude install -D postfix
The following NEW packages will be installed:
  file{a} (R: mime-support, S: exim4-base, S: libmagic1)  
  libexpat1{a} (D: python2.6)  libmagic1{a} (D: file)  
  libsasl2-2{a} (D: libsasl2-modules, D: postfix)  
  libsasl2-modules{a} (R: libsasl2-2, S: postfix)  
  mime-support{a} (D: python2.6)  openssl{a} (D: ssl-cert, S: exim4-base)  
  postfix{b} (C: mail-transport-agent)  
  python{a} (R: postfix, R: python-minimal)  python-minimal{a} (D: python)  
  python2.6{a} (D: python, R: python2.6-minimal)  
  python2.6-minimal{a} (D: python-minimal, D: python2.6)  
  ssl-cert{a} (D: postfix)  
0 packages upgraded, 13 newly installed, 0 to remove and 0 not upgraded.
Need to get 7366 kB of archives. After unpacking 25.2 MB will be used.
The following packages have unmet dependencies:
  postfix: Conflicts: mail-transport-agent which is a virtual package.
  exim4-daemon-light: Conflicts: mail-transport-agent which is a virtual package.
  exim4-config: Conflicts: postfix but 2.7.1-1+squeeze1 is to be installed.
The following actions will resolve these dependencies:

     Remove the following packages:
1)     exim4-base                  
2)     exim4-config                
3)     exim4-daemon-light          

Accept this solution? [Y/n/q/?] 

I'll leave this open as wishlist bug. Feel free to close it if the
explanation of the found solution as shown above solves the issue for
you already.

		Regards, Axel
-- 
 ,''`.  |  Axel Beckert <abe at debian.org>, http://people.debian.org/~abe/
: :' :  |  Debian Developer, ftp.ch.debian.org Admin
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