libc6-dbgsym:amd64 trying to overwrite '/usr/lib/debug/lib/x86_64-linux-gnu/libnsl-2.17.so' from libc6-dbg:amd64 2.17-93ubuntu4

[Rüdiger Sonderfeld]

Trying to install libc6-dbgsym causes a conflict with libc6-dbg: dpkg: error processing /var/cache/apt/archives/libc6-dbgsym_2.17-93ubuntu4_amd64.ddeb (--unpack): trying to overwrite '/usr/lib/debug/lib/x86_64-linux-gnu/libnsl-2.17.so', which is also in package libc6-dbg:amd64 2.17-93ubuntu4

Full error message:

$ sudo apt-get install libc6-dbgsym
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following NEW packages will be installed:
  libc6-dbgsym
0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
Need to get 3,387 kB of archives.
After this operation, 23.0 MB of additional disk space will be used.
Get:1 http://ddebs.ubuntu.com/ saucy/main libc6-dbgsym amd64 2.17-93ubuntu4 [3,387 kB]
Fetched 3,387 kB in 17s (197 kB/s)
Selecting previously unselected package libc6-dbgsym:amd64.
(Reading database ... 646933 files and directories currently installed.)
Unpacking libc6-dbgsym:amd64 (from .../libc6-dbgsym_2.17-93ubuntu4_amd64.ddeb) ...
dpkg: error processing /var/cache/apt/archives/libc6-dbgsym_2.17-93ubuntu4_amd64.ddeb (--unpack):
 trying to overwrite '/usr/lib/debug/lib/x86_64-linux-gnu/libnsl-2.17.so', which is also in package libc6-dbg:amd64 2.17-93ubuntu4
dpkg-deb: error: subprocess paste was killed by signal (Broken pipe)
Errors were encountered while processing:
 /var/cache/apt/archives/libc6-dbgsym_2.17-93ubuntu4_amd64.ddeb
E: Sub-process /usr/bin/dpkg returned an error code (1)

$ dpkg -l libc6* | grep ^ii
ii libc6:amd64 2.17-93ubuntu4 amd64 Embedded GNU C Library: Shared libraries
ii libc6:i386 2.17-93ubuntu4 i386 Embedded GNU C Library: Shared libraries
ii libc6-dbg:amd64 2.17-93ubuntu4 amd64 Embedded GNU C Library: detached debugging symbols
ii libc6-dev:amd64 2.17-93ubuntu4 amd64 Embedded GNU C Library: Development Libraries and Header Files
ii libc6-dev-i386 2.17-93ubuntu4 amd64 Embedded GNU C Library: 32-bit development libraries for AMD64
ii libc6-dev-x32 2.17-93ubuntu4 amd64 Embedded GNU C Library: X32 ABI Development Libraries for AMD64
ii libc6-i386 2.17-93ubuntu4 amd64 Embedded GNU C Library: 32-bit shared libraries for AMD64
ii libc6-x32 2.17-93ubuntu4 amd64 Embedded GNU C Library: X32 ABI Shared libraries for AMD64

$ apt-cache policy libc6-dbg
libc6-dbg:
  Installed: 2.17-93ubuntu4
  Candidate: 2.17-93ubuntu4
  Version table:
 *** 2.17-93ubuntu4 0
        500 http://de.archive.ubuntu.com/ubuntu/ saucy/main amd64 Packages
        100 /var/lib/dpkg/status

$ apt-cache policy libc6-dbgsym
libc6-dbgsym:
  Installed: (none)
  Candidate: 2.17-93ubuntu4
  Version table:
     2.17-93ubuntu4 0
        500 http://ddebs.ubuntu.com/ saucy/main amd64 Packages
        500 http://ddebs.ubuntu.com/ saucy/main amd64 Packages

$ lsb_release -rd
Description: Ubuntu 13.10
Release: 13.10

[Rüdiger Sonderfeld (ruediger-c-plusplus)]

Slightly OT: the app port error reporter claimed that libc6-dbgsym is not an official package. Is this official policy or did it simply fail to consider ddebs.ubuntu.com as official ubuntu repo?