I experienced the same problem as the initial submitter, attached is some brief diagnosis.
# dpkg --debug=3 -i /var/cache/apt/archives/roundup_1.4.9-1_all.deb (Reading database ... 58618 files and directories currently installed.) Preparing to replace roundup 1.4.9-1 (using .../roundup_1.4.9-1_all.deb) ... D000001: process_archive oldversionstatus=broken due to postinst failure D000002: fork/exec /var/lib/dpkg/info/roundup.prerm ( upgrade 1.4.9-1 ) Stopping Roundup HTTP-Server:start-stop-daemon: warning: failed to kill 5842: No such process roundup-server. D000002: fork/exec /var/lib/dpkg/tmp.ci/preinst ( upgrade 1.4.9-1 ) Unpacking replacement roundup ... D000002: fork/exec /var/lib/dpkg/info/roundup.postrm ( upgrade 1.4.9-1 ) D000001: process_archive updating info directory D000002: process_archive info installed /var/lib/dpkg/tmp.ci/preinst as /var/lib/dpkg/info//roundup.preinst D000002: process_archive info installed /var/lib/dpkg/tmp.ci/postinst as /var/lib/dpkg/info//roundup.postinst D000002: process_archive info installed /var/lib/dpkg/tmp.ci/prerm as /var/lib/dpkg/info//roundup.prerm D000002: process_archive info installed /var/lib/dpkg/tmp.ci/postrm as /var/lib/dpkg/info//roundup.postrm D000002: process_archive info installed /var/lib/dpkg/tmp.ci/conffiles as /var/lib/dpkg/info//roundup.conffiles D000002: process_archive info installed /var/lib/dpkg/tmp.ci/md5sums as /var/lib/dpkg/info//roundup.md5sums D000002: process_archive tmp.ci script/file `.' contains dot D000002: process_archive tmp.ci script/file `..' contains dot D000002: process_archive tmp.ci script/file `/var/lib/dpkg/tmp.ci/control' is control Setting up roundup (1.4.9-1) ... D000001: deferred_configure updating conffiles D000002: fork/exec /var/lib/dpkg/info/roundup.postinst ( configure 1.4.9-1 ) file does not exist: /build/lib/roundup/__init__.py file does not exist: /build/lib/roundup/actions.py file does not exist: /build/lib/roundup/admin.py file does not exist: /build/lib/roundup/anypy/__init__.py file does not exist: /build/lib/roundup/anypy/hashlib_.py file does not exist: /build/lib/roundup/anypy/sets_.py file does not exist: /build/lib/roundup/backends/__init__.py <....> # bash -x /var/lib/dpkg/info/roundup.postinst configure 1.4.9-1 + set -e + '[' -d /var/service ']' + which pycentral + pycentral pkginstall roundup file does not exist: /build/lib/roundup/__init__.py file does not exist: /build/lib/roundup/actions.py <....> # pycentral pkginstall roundup file does not exist: /build/lib/roundup/__init__.py file does not exist: /build/lib/roundup/actions.py file does not exist: /build/lib/roundup/admin.py <....> # dpkg -L roundup | grep pyshared-data /usr/share/pyshared-data /usr/share/pyshared-data/roundup # head /usr/share/pyshared-data/roundup [python-package] format = 1 python-version = 2.4, 2.5 [pycentral] version = 0.6.11 include-links = 0 [files] /build/lib/roundup/mailgw.py=f /build/lib/roundup/init.py=f /build/lib/roundup/security.py=f