现在我升级、安装任何软件被因安装的是python-crypto_2.6.1-6build1而不是python-crypto_2.6.1-6ubuntu0.16.04.2被迫无法前进；
google到的一些方法都没能奏效（apt -f install之类）。
请问：我该如何先卸载了python-crypto_2.6.1-6build1再去安装python-crypto_2.6.1-6ubuntu0.16.04.2 ？？？


$ sudo apt -y upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
You might want to run 'apt-get -f install' to correct these.
The following packages have unmet dependencies:
python-crypto-dbg : Depends: python-crypto (= 2.6.1-6ubuntu0.16.04.2) but 2.6.1-6build1 is installed
E: Unmet dependencies. Try using -f.

执行以下指令将结果全部复制贴上来，不要节选

$cat /etc/issue
Ubuntu 16.04.2 LTS \n \l

$dpkg --print-architecture
amd64

$dpkg -l | grep python-crypto
iFR python-crypto 2.6.1-6build1 amd64 cryptographic algorithms and protocols for Python
iU python-crypto-dbg 2.6.1-6ubuntu0.16.04.2 amd64 cryptographic algorithms and protocols for Python (debug extension)
ii python-crypto-doc 2.6.1-6ubuntu0.16.04.2 all cryptographic algorithms and protocols for Python (documentation)

$apt-cache policy python-crypto python-crypto-dbg
python-crypto:
Installed: 2.6.1-6build1
Candidate: 2.6.1-6ubuntu0.16.04.2
Version table:
2.6.1-6ubuntu0.16.04.2 500
500 http://mirrors.aliyun.com/ubuntu xenial-updates/main amd64 Packages
500 http://mirrors.aliyun.com/ubuntu xenial-security/main amd64 Packages
500 http://cz.archive.ubuntu.com/ubuntu xenial-updates/main amd64 Packages
500 http://security.ubuntu.com/ubuntu xenial-security/main amd64 Packages
*** 2.6.1-6build1 500
500 http://mirrors.aliyun.com/ubuntu xenial/main amd64 Packages
100 /var/lib/dpkg/status
python-crypto-dbg:
Installed: 2.6.1-6ubuntu0.16.04.2
Candidate: 2.6.1-6ubuntu0.16.04.2
Version table:
*** 2.6.1-6ubuntu0.16.04.2 500
500 http://mirrors.aliyun.com/ubuntu xenial-updates/main amd64 Packages
500 http://mirrors.aliyun.com/ubuntu xenial-security/main amd64 Packages
500 http://cz.archive.ubuntu.com/ubuntu xenial-updates/main amd64 Packages
500 http://security.ubuntu.com/ubuntu xenial-security/main amd64 Packages
100 /var/lib/dpkg/status
2.6.1-6build1 500
500 http://mirrors.aliyun.com/ubuntu xenial/main amd64 Packages

$cat /var/log/apt/history.log | grep -C5 python-crypto
Start-Date: 2017-03-21 19:35:17
Commandline: apt -f install
Upgrade: python-crypto:amd64 (2.6.1-6build1, 2.6.1-6ubuntu0.16.04.2)
Error: Sub-process /usr/bin/dpkg returned an error code (1)
End-Date: 2017-03-21 19:35:19

Start-Date: 2017-03-21 19:36:13
Commandline: apt -f install /var/cache/apt/archives/python-crypto_2.6.1-6ubuntu0.16.04.2_amd64.deb
Upgrade: python-crypto:amd64 (2.6.1-6build1, 2.6.1-6ubuntu0.16.04.2)
Error: Sub-process /usr/bin/dpkg returned an error code (1)
End-Date: 2017-03-21 19:36:14