Your root file system is a btrfs file system. This is not supported by the boot loader used by default by this installer.
Anagraw-inek·inem n yifuyla aẓar d anagraw n yifuyla btrfs. Ur yettusefrak ara sɣur usalay n usenker i yettusqedcen s wudem amezwer s usebdad-a.