If I sudo man it works fine, otherwise I'm getting
~$ man ls
fuse: mount failed: Permission denied
Cannot mount AppImage, please check your FUSE setup.
You might still be able to extract the contents of this AppImage
if you run it with the --appimage-extract option.
See https://github.com/AppImage/AppImageKit/wiki/FUSE
for more information
open dir error: No such file or directory
for reference, setting the MANPAGER as per neovim help
export MANPAGER='nvim +Man!'
:Man command works fine from inside nvim.