Package: dpkg Version: 1.4.1.13 When an error occurs during unpacking, dpkg should unwind all the way back to step 1. This means running new-postrm abort-upgrade/abort-install, as well as old-postinst abort-upgrade. This is necessary because the old prerm and the new preinst have both been run during an upgrade.
Here is an example where not doing this may break perl: $ sudo dpkg -i /mnt/big/debian/repo/dists/potato/main/binary-i386/interpreters/perl-5.005_5.005.03-4.deb (Reading database ... 74984 files and directories currently installed.) Preparing to replace perl-5.005 5.005.03-3 (using .../perl-5.005_5.005.03-4.deb) ... <deleted output from prerm script> Unpacking replacement perl-5.005 ... dpkg-deb (subprocess): unexpected end of file in member data in /mnt/big/debian/repo/dists/potato/main/binary-i386/interpreters/perl-5.005_5.005.03-4.deb gzip: stdin: unexpected end of file dpkg-deb: subprocess gzip -dc returned error exit status 1 dpkg: error processing /mnt/big/debian/repo/dists/potato/main/binary-i386/interpreters/perl-5.005_5.005.03-4.deb (--install): subprocess dpkg-deb --fsys-tarfile (EOF) returned error exit status 2 Errors were encountered while processing: /mnt/big/debian/repo/dists/potato/main/binary-i386/interpreters/perl-5.005_5.005.03-4.deb Afterwards, the system did not have an asm link for perl because it was removed by the prerm script. -- System Information Debian Release: potato Kernel Version: Linux gondor 2.2.12 #2 Sat Sep 18 12:11:40 EST 1999 i586 unknown Versions of the packages dpkg depends on: ii libc6 2.1.2-1 GNU C Library: Shared libraries and timezone ii libncurses4 4.2-3.2 Shared libraries for terminal handling ii libstdc++2.10 2.95.2-0pre2 The GNU stdc++ library
