Is this https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=774941 ? Sounds very much like it except that that bug was fixed in 1.0.24-9. Quite possibly the fix is incomplete when updating from a broken version.
** Bug watch added: Debian Bug tracker #774941 http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=774941 -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to sane-backends in Ubuntu. https://bugs.launchpad.net/bugs/1510676 Title: package sane-utils 1.0.25+git20150528-1ubuntu2 failed to install/upgrade: subprocess installed post-installation script returned error exit status 8 Status in sane-backends package in Ubuntu: Confirmed Bug description: Encountered during upgrade from Vivid to Wily (15.04 to 15.10) ProblemType: Package DistroRelease: Ubuntu 15.10 Package: sane-utils 1.0.25+git20150528-1ubuntu2 ProcVersionSignature: Ubuntu 3.19.0-31.36-generic 3.19.8-ckt7 Uname: Linux 3.19.0-31-generic x86_64 NonfreeKernelModules: zfs zunicode zcommon znvpair zavl ApportVersion: 2.19.1-0ubuntu3 Architecture: amd64 Date: Thu Oct 22 22:07:26 2015 DuplicateSignature: package:sane-utils:1.0.25+git20150528-1ubuntu2:subprocess installed post-installation script returned error exit status 8 ErrorMessage: subprocess installed post-installation script returned error exit status 8 InstallationDate: Installed on 2013-03-02 (964 days ago) InstallationMedia: Ubuntu-Server 12.10 "Quantal Quetzal" - Release amd64 (20121017.2) RelatedPackageVersions: dpkg 1.18.2ubuntu5 apt 1.0.10.2ubuntu1 SourcePackage: sane-backends Title: package sane-utils 1.0.25+git20150528-1ubuntu2 failed to install/upgrade: subprocess installed post-installation script returned error exit status 8 UpgradeStatus: Upgraded to wily on 2015-10-23 (0 days ago) mtime.conffile..etc.default.saned: 2015-04-28T00:00:59.104233 mtime.conffile..etc.sane.d.saned.conf: 2013-09-09T00:21:31.828295 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/sane-backends/+bug/1510676/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp