package apt found 598669 0.7.26~exp11 tags 598669 patch thanks 2010/10/1 Joey Hess <joeyh@debian.org>: > Investigating (0) exim4 [ i386 ] < 4.72-1 > ( mail ) > Broken exim4:i386 Depends on exim4-daemon-light [ i386 ] < 4.72-1 > ( mail ) > Considering exim4-daemon-light:i386 1 as a solution to exim4:i386 19 > Added exim4-daemon-light:i386 to the remove list > Broken exim4:i386 Depends on exim4-daemon-heavy [ i386 ] < none -> 4.72-1 > ( mail ) > Considering exim4-daemon-heavy:i386 1 as a solution to exim4:i386 19 > Try Installing exim4-daemon-heavy [ i386 ] < none -> 4.72-1 > ( mail ) before changing exim4:i386 > Fixing exim4:i386 via keep of exim4-daemon-light:i386 (Not that i haven't expected problems with this "Try installing before changing" thing…) The problem is that exim4 is a metapackage which or-depends on light and heavy and so APT tries to fix here exim4 by installing heavy -- which in his installation removes postfix -- bad as hell: APT shouldn't decide to remove a package the user has explicitly requested for installation. > aptitude has no trouble finding the obvious solution. You can disable the "try installing before changing" thing in this situation to see what APT will do in a fixed version: -o pkgProblemResolver::FixByInstall=0 As you can see it tries hard to let exim4 stay on the system, so while the solution looks maybe obvious, it involves a lot of calculation to find the "obvious"… Best regards David Kalnischkies
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