@mitu From what directory do i do the
apt install libsdl2-net-2.0-0?

It doesn't matter.

and then from what directory do i do the standalone
installation and extraction from https://buildbot.scummvm.org/dailybuild ... 6e6.tar.xz ?

and in which order?

Not sure what you mean here, your post indicated that you've already done this and you get an error when you're executing the new scummvm. Just extract the archive obtained from the ScummVM Buildbot using site with tar, i.e.

tar xJf /path/to/<archive_file>

and you'll be getting a new folder containing the ScummVM installation. You can then rename/move the folder as you like.

@tsukisuperior can use

sudo CC="whatever" ./retropie_setup.sh

This may not work for all modules as some module code may override it.

distcc can be used automatically by setting DISTCC_HOSTS="192.168.0.1/4,lzo" etc in the same way. It will get added to start of system PATH and added to MAKEFLAGS also.