Q: How to install latest Code::Blocks from tar.xz? How to install latest Code::Blocks using codeblocks_17.12-1_amd64_stable.tar.xz?
Software center has an old version and I am not able to configure. How to install? Why is there no documentation for installing?

A: You should extract downloaded archive with
cd ~/Downloads
wget https://kent.dl.sourceforge.net/project/codeblocks/Binaries/17.12/Linux/Debian%20stable/codeblocks_17.12-1_amd64_stable.tar.xz
tar -xf codeblocks_17.12-1_amd64_stable.tar.xz

Then install extracted deb-packages:
sudo dpkg -i *17.12*.deb

And finally install missed dependencies:
sudo apt-get install -f

Please note that codeblocks-contrib will be removed on 16.04 LTS and on 18.04 LTS because of missed libhunspell-1.4-0 dependency.
Do not forget to install compiler such as GCC.

A: if you apply the same steps already explained

sudo dpkg -i 17.12.deb

and 

sudo apt-get install -f

But with debian testing .deb instead of debian stable, libhunspell version is in sync and all work ok, including the codeblocks-contrib package.
