It’s easy if you are ready to build on linux, just go to to my github download it ,

GitHub r-type/vice3.0-libretro vice3.0-libretro - Versatile Commodore 8-bit Emulator version 3.0 LIBRETRO WIP

then you have to compile it yourself with

CC=gcc make -f Makefile.libretro -j10

and you ll end up with a x64_libretro.so

Remember it’s a WIP core for now and not as great as the official vice emulator.

then launch it with

retroarch -L x64_libretro.so /path/your_game.d64 (or whatever if you have crt/bin/d64.gz/t64 …)

you can also use a .vicerc or use cmdline to make more complicated load like retroarch -L x64_libretro.so "x64 -autostart \"/PRIVATE/games/Lemmings [Side A].d64\" -flipname ./lemming.vfl "

Finally you can also setup an ide64 solution to load game from an virtual hdd in vice ,it’s a little complicated to setup but you will end up with something like this

Video:https://vid dot me/qhxQ