Hi,
I've been building master branch for Odroid C2 and encountered encoding issues (build crashed).
Turns out I've only enabled pl_PL.UTF-8 on my system, after I've enabled en_US.UTF-8 everything went fine.
Error was related to python package meson.
This more a configuration issue than bug, but validating this earlier on would help avoid such issue.
Specially that this is my first attempt to build Libreelec.
Best regards and keep up the great work! 
Last night myself and a colleague both tried clean builds with LANG=pl_PL.UTF-8 in order to try and narrow down the cause of the failure, but our builds were successful (we were both building master, I built Odroid_C2, my colleague built RPi2).
In my case I built with the following patch on my Ubuntu 17.10 build system (which uses en_GB.UTF-8 by default): 12K6
Would you mind testing the following patch on your Docker container to see if it has any effect? 13e9
You should restore your system to the initial failure condition, ie. pl_PL.UTF-8 as the system default LANG, before the test.
This isn't necessarily a long term fix (although if it works then it could be), but it might also help shed more light on the issue.
Can you also confirm your command line when starting your build, and if you are building with any other patches?
I've realized later by reading posts that I should use ubuntu for my building. I didn't pay attention earlier and build it on Arch linux.
No docker containers involved for that build.
I will try to disable the US locale after Easter and recreate the issue, then apply the patch.
As for the command line, as per instructions on the wiki.
I've first downloaded all the sources and then run:
PROJECT=Amlogic DEVICE=Odroid_C2 ARCH=arm make imageThe build booted properly btw, I've only attempted it to check if everything works before I try to add support for my wifi module (Archer T2UH).
It looks like nice weekend project 