Today I get the following error when running “apt-get”:

This problems happens when I run Python code which uses “import matplotlib.pyplot as plt” or “import axelrod as axl”. Both of them use “tk”.

Synchronous queues are similar to rendezvous channels used in CSP and Ada. They are well suited for handoff designs, in which an object running in one thread must sync up with an object running in another thread in order to hand it some information, event, or task. –From Java offical document here

From here and here.

If I want to rebuild an Ubuntu environment as an existing one, a question is that how I can list all the manually installed PPAs and pacakges. Here is the answer.

After I ran “apt-get dist-upgrade” and encountered an unexpecting exit, rerunning “apt-get dist-upgrade” gives me the following issue:

From here.

Nix is a powerful package manager for Linux and other Unix systems that makes package management reliable and reproducible. I install Nix to use boot.