dpkg "trying to overwrite '<file>' , which is also in package <pkg>" error message is not multi-arch compliant

[Michael Schaller]

Hi everyone,

On Trusty the dpkg error message "trying to overwrite '<file>' , which is also in package <pkg>" is not multi-arch compliant because it lacks the architecture of foreign packages.

Current/faulty output from an amd64 install:
Preparing to unpack deb-file-conflict-i386-2_1_i386.deb ...
Unpacking deb-file-conflict-i386-2 (1) ...
dpkg: error processing archive deb-file-conflict-i386-2_1_i386.deb (--install):
 trying to overwrite '/var/lib/conflicting-file/conflicting-file', which is also in package deb-file-conflict-i386-1 1
Errors were encountered while processing:
 deb-file-conflict-i386-2_1_i386.deb

The correct output on an amd64 install would be:
Preparing to unpack deb-file-conflict-i386-2_1_i386.deb ...
Unpacking deb-file-conflict-i386-2:i386 (1) ...
dpkg: error processing archive deb-file-conflict-i386-2_1_i386.deb (--install):
 trying to overwrite '/var/lib/conflicting-file/conflicting-file', which is also in package deb-file-conflict-i386-1:i386 1
Errors were encountered while processing:
 deb-file-conflict-i386-2_1_i386.deb

This faulty error message makes it harder to fix conflicting file issues because the error message can be misleading. Furthermore this is a regression as the error message in Precise shows the architecture.

Best,

Michael