When trying to load core RetroArch gives
[ERROR] Failed to open libretro core: .../.var/app/org.libretro.RetroArch/config/retroarch/cores/ppsspp_libretro.so"
[ERROR] Error(s): libsnappy.so.1: cannot open shared object file: No such file or directory
Of course snappy package is installed and libsnappy.so.1 is there
Mind creating an issue over at https://github.com/flathub/org.libretro.RetroArch ?
You're unable to open the PPSSPP core. We'll need to add libsnappy to the FlatHub install.
Here is a better solution.
git clone https://github.com/libretro/RetroArch/
cd RetroArch
./configure && make && ./retroarch
Made an issue over at https://github.com/flathub/org.libretro.RetroArch/issues/32 .... Feel free to close this one.