Example
with TempFS() as temp_fs:
temp_fs_sys_path = temp_fs.root_path # raises AttributeError since temp_fs is of type FS
To get around this you need to do:
temp_fs_root_sys_path = temp_fs.getsyspath('')
There may be other OSFS/TempFS specific attributes that may fail due to this.
TempFS.__enter__ return type should be TempFS, not FS.