Thanks for your answer.
Well, debian doesn't have code blocks 17 in its repo, I was forced to install it from other sources. But since I could find 17.12 in a deb package and since 17.12 has been out for quite a while, I'm surprised that I cannot find it for download anywhere (well, I have found codeblocks-contrib-17.12 in a RPN package, but that doesn't help).
I switched to 17.12 because of an "ingooglable" bug that all my installations of Code::Blocks has suffered from since 2014 (on various debian x86 and debian AMD64). At random some file windows are completely grayed out when switching to their tab (for instance, having "main.c" and "global.h" in different tabs, working with main.c and switching to global.h and find that the window is all but gray). Nothing except restarting Code::Blocks helps. No one on this planet seems to experience this irritating and show-stopping bug except me. At least 17.12 worked.
Building a tool chain should be easy. It often is. I don't know why I even need the "-contrib" part, as this should be easy. My AVR toolchain works fine, my AMD64-gcc toolchain works fine, my gcc Fortran toolchaing works fine. All in Code::Blocks. But, the question of tool chain is best to leave to another thread. My problem right now are the impossibility of getting codeblocks-contrib-17.12. I cannot understand the lack of download links on the main page. Since there is a RPN package to be found, and probably a windows installer, a deb package should be a no-brainer. Or at least sources and build instructions.