$sudo aptitude install libssl-dev
The following NEW packages will be installed:
libssl-dev{b}
The following packages are RECOMMENDED but will NOT be installed:
libssl-doc
0 packages upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
Need to get 1,528 kB of archives. After unpacking 6,179 kB will be used.
The following packages have unmet dependencies:
libssl-dev : Depends: libssl1.0.0 (= 1.0.1-4ubuntu5) but 1.0.1-4ubuntu5.3 is installed.
Depends: zlib1g-dev but it is not going to be installed.
The following actions will resolve these dependencies:
Keep the following packages at their current version:
1) libssl-dev [Not Installed]
Accept this solution? [Y/n/q/?] n
The following actions will resolve these dependencies:
Install the following packages:
1) zlib1g-dev [1:1.2.3.4.dfsg-3ubuntu4 (precise)]
Downgrade the following packages:
2) libssl1.0.0 [1.0.1-4ubuntu5.3 (now) -> 1.0.1-4ubuntu5 (precise-updates)]
Accept this solution? [Y/n/q/?] y
The following packages will be DOWNGRADED:
libssl1.0.0
The following NEW packages will be installed:
libssl-dev zlib1g-dev{a}
The following packages are RECOMMENDED but will NOT be installed:
libssl-doc
0 packages upgraded, 2 newly installed, 1 downgraded, 0 to remove and 0 not upgraded.
Need to get 2,707 kB of archives. After unpacking 6,575 kB will be used.
Do you want to continue? [Y/n/?] y
Get: 1 http://mirror.lupaworld.com/ubuntu/ precise-updates/main libssl1.0.0 amd64 1.0.1-4ubuntu5 [1,013 kB]
Get: 2 http://mirror.lupaworld.com/ubuntu/ precise/main zlib1g-dev amd64 1:1.2.3.4.dfsg-3ubuntu4 [165 kB]
Get: 3 http://mirror.lupaworld.com/ubuntu/ precise-updates/main libssl-dev amd64 1.0.1-4ubuntu5 [1,528 kB]
Fetched 2,707 kB in 5s (503 kB/s)
Preconfiguring packages ...
dpkg: warning: downgrading libssl1.0.0 from 1.0.1-4ubuntu5.3 to 1.0.1-4ubuntu5.
(Reading database ... 150648 files and directories currently installed.)
Preparing to replace libssl1.0.0 1.0.1-4ubuntu5.3 (using .../libssl1.0.0_1.0.1-4ubuntu5_amd64.deb) ...
Unpacking replacement libssl1.0.0 ...
Setting up libssl1.0.0 (1.0.1-4ubuntu5) ...
Processing triggers for libc-bin ...
ldconfig deferred processing now taking place
Selecting previously unselected package zlib1g-dev.
(Reading database ... 150648 files and directories currently installed.)
Unpacking zlib1g-dev (from .../zlib1g-dev_1%3a1.2.3.4.dfsg-3ubuntu4_amd64.deb) ...
Selecting previously unselected package libssl-dev.
Unpacking libssl-dev (from .../libssl-dev_1.0.1-4ubuntu5_amd64.deb) ...
Processing triggers for man-db ...
Setting up zlib1g-dev (1:1.2.3.4.dfsg-3ubuntu4) ...
Setting up libssl-dev (1.0.1-4ubuntu5) ...