Status now:
LANG=C apt-cache policy libc6 libc6:i386
libc6:
Installed: 2.19-7
Candidate: 2.19-9
Version table:
2.19-9 0
500 http://ftp.debian.de/debian/ unstable/main amd64 Packages
*** 2.19-7 0
500 http://debian.siduction.org/ testing/main amd64 Packages
100 /var/lib/dpkg/status
2.13-38+deb7u2 0
500 http://debian.siduction.org/ stable/main amd64 Packages
libc6:i386:
Installed: 2.19-7
Candidate: 2.19-7
Version table:
*** 2.19-7 0
500 http://ftp.debian.de/debian/ unstable/main i386 Packages
500 http://debian.siduction.org/ testing/main i386 Packages
100 /var/lib/dpkg/status
2.13-38+deb7u2 0
500 http://debian.siduction.org/ stable/main i386 Packages
So updating a multiarch system will break the system - please wait and stay tuned ...