# aptitude install certbot
The following NEW packages will be installed:
certbot python-acme{ab} python-certbot{ab} python-configargparse{a} python-configobj{a} python-dialog{a}
python-dnspython{a} python-mock{a} python-ndg-httpsclient{a} python-parsedatetime{a} python-pyasn1{a}
python-pyicu{a} python-requests{a} python-rfc3339{a} python-tz{a} python-urllib3{a} python-zope.component{a}
python-zope.event{a} python-zope.interface{a}
0 packages upgraded, 19 newly installed, 0 to remove and 0 not upgraded.
Need to get 1,206 kB of archives. After unpacking 6,138 kB will be used.
The following packages have unmet dependencies:
python-acme : Depends: python-openssl (>= 0.15) but 0.14-1 is installed.
Depends: python-cryptography (>= 0.8) but 0.6.1-1 is installed.
Depends: python-setuptools (>= 11.3~) but 5.5.1-1 is installed.
python-certbot : Depends: python-cryptography (>= 0.7) but 0.6.1-1 is installed.
The following actions will resolve these dependencies:
Keep the following packages at their current version:
1) certbot [Not Installed]
2) python-acme [Not Installed]
3) python-certbot [Not Installed]
Accept this solution? [Y/n/q/?] n
The following actions will resolve these dependencies:
Remove the following packages:
1) python-cffi
Install the following packages:
2) python-cffi-backend [1.4.2-2~bpo8+1 (jessie-backports)]
3) python-enum34 [1.0.3-1 (stable)]
4) python-idna [2.0-3~bpo8+1 (jessie-backports)]
5) python-ipaddress [1.0.16-1~bpo8+1 (jessie-backports)]
6) python-pyasn1 [0.1.9-1~bpo8+1 (jessie-backports)]
Upgrade the following packages:
7) python-cryptography [0.6.1-1 (now, stable) -> 1.3.4-1~bpo8+2 (jessie-backports)]
8) python-openssl [0.14-1 (now, stable) -> 16.0.0-1~bpo8+1 (jessie-backports)]
9) python-pkg-resources [5.5.1-1 (now, stable) -> 20.10.1-1.1~bpo8+1 (jessie-backports)]
10) python-setuptools [5.5.1-1 (now, stable) -> 20.10.1-1.1~bpo8+1 (jessie-backports)]
Accept this solution? [Y/n/q/?]
Newly updated debian jessie stable will make it a bit difficult to install certbot with backports!