gcc 9 compilation is broken

[witaly-iwanow]

I'm getting these errors on gcc 9.3.0 (Ubuntu 20.04). A bit of googling revealed that it's usually resolved with adding an = operator declared as = default. I can't figure it out though, gotta love templates - errors are as confusing as ever, not much has changed in the last 15 years since I started dabbling in C++. TIA
salsify-build-error-log.txt

[witaly-iwanow]

Looks like replacing shady const Context & operator=( const Context & ) { return *this; } with const Context & operator=( const Context & ) = delete; does the trick

[witaly-iwanow]

I have it fixed in my fork (https://github.com/witaly-iwanow/alfalfa), along with one more Ubuntu 20.04 fix. Let me know if you're interested in merging those (the second fix can probably break things for older libx264-dev builds)