[Python-modules-team] Bug#866664: python3-cairo: In Buster, trying to update python3-cairo doesn't work because it's in sid, not testing

[debianuser]

Package: python3-cairo
Version: 1.10.0+dfsg-5+b1
Severity: important

Dear Maintainer,

Trying to upgrade python3-cairo in Buster gives the following:

root at debian:/home/alex# apt upgrade
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Calculating upgrade... Done
The following packages will be upgraded:
  python3-cairo
1 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
21 not fully installed or removed.
Need to get 0 B/46.9 MB of archives.
After this operation, 108 MB of additional disk space will be used.
Do you want to continue? [Y/n] y
Retrieving bug reports... Done
Parsing Found/Fixed information... Done
Reading changelogs... Done
(Reading database ... 212610 files and directories currently installed.)
Preparing to unpack .../python3-cairo_1.10.0+dfsg-5+b2_amd64.deb ...
Unpacking python3-cairo (1.10.0+dfsg-5+b2) over (1.10.0+dfsg-5+b1) ...
dpkg: error processing archive /var/cache/apt/archives/python3-cairo_1.10.0+dfsg-5+b2_amd64.deb (--unpack):
 trying to overwrite '/usr/lib/python2.7/dist-packages/debconf.py', which is also in package debconf 1.5.61
dpkg-deb: error: subprocess paste was killed by signal (Broken pipe)
Errors were encountered while processing:
 /var/cache/apt/archives/python3-cairo_1.10.0+dfsg-5+b2_amd64.deb
E: Sub-process /usr/bin/dpkg returned an error code (1)

The reason for this, apparently, is that the package in question is in unstable and not testing.


-- System Information:
Debian Release: 9.0
  APT prefers testing
  APT policy: (500, 'testing')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.9.0-3-amd64 (SMP w/4 CPU cores)
Locale: LANG=en_CA.UTF-8, LC_CTYPE=en_CA.UTF-8 (charmap=UTF-8), LANGUAGE=en_CA:en (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages python3-cairo depends on:
ii  libc6      2.24-12
ii  libcairo2  1.14.8-1
ii  python3    3.5.3-1

python3-cairo recommends no packages.

python3-cairo suggests no packages.

-- no debconf information