annadane@debian:~$ aptitude dist-upgrade -s
The following packages will be REMOVED:
  libbind9-140{u} libdns162{u} libisc160{u} libisccc140{u} libisccfg140{u} liblwres141{u} libperl5.24{u} libpython3.5-minimal{u}
  libpython3.5-stdlib{u} python3.5{u} python3.5-minimal{u} rename{u}
The following packages will be upgraded:
  python3-urllib3
1 packages upgraded, 0 newly installed, 12 to remove and 0 not upgraded.
Need to get 97.9 kB of archives. After unpacking 52.0 MB will be freed.
The following packages have unmet dependencies:
 python3-requests : Depends: python3-urllib3 (< 1.22) but 1.22-1 is to be installed
The following actions will resolve these dependencies:

     Keep the following packages at their current version:
1)     python3-urllib3 [1.21.1-1 (now)]



Accept this solution? [Y/n/q/?]

annadane@debian:~$ apt-cache policy python3-urllib3 python3-requests
python3-urllib3:
  Installed: 1.21.1-1
  Candidate: 1.22-1
  Version table:
     1.22-1 500
        500 http://ftp.ca.debian.org/debian sid/main amd64 Packages
 *** 1.21.1-1 100
        100 /var/lib/dpkg/status
python3-requests:
  Installed: 2.18.1-1
  Candidate: 2.18.1-1
  Version table:
 *** 2.18.1-1 500
        500 http://ftp.ca.debian.org/debian sid/main amd64 Packages
        100 /var/lib/dpkg/status