Please read the Troubleshooting section in the readme.
Also, GCC 6.3 is a bit on the old end and I don't know if it compiles anymore. It might work, but I'd recommend to update to a MinGW version that ships at least GCC 7.3.
That'll teach me to think I might be able to get away installing Debian's packages version. Thank you. I'll try that (both suggestions).
I may have to throw the towel in...I have been trying to build mingw-w64 all day...the fundamental problem is the instruction which call for a "mingw-w32-1.0-bin_x86_64-linux_[yyyymmdd].tar.bz2" file I cannot locate. I even download something that clearly only needed unarching (mostly into /usr) and this seem to take me back a step (or two). If I cannot delploy mingw-64 that employs an more up-to-date gcc I not sure how to proceed.
I tried the Debian Backports version that features GCC 7.3...same result.
Yes, you need to perform the update-alternatives step mentioned in the readme. It is not optional.
Done sir, multiple times.
It's obvious that your MinGW doesn't support pthreads for whatever reason, but how to get that to work is not something I can help you with. Might be worth asking elsewhere.
Nothing extracted yet.
I'm sure I've made a simple yet fundamental error. This is my output from running
./package-release.sh master /your/target/directory --no-packagehttps://pastebin.com/8GUwsChT