Comment 4 for bug 1917174

Under liveusb and during installation

ubuntu@ubuntu:journalctl -g attention
-- Logs begin at Tue 2021-03-02 19:51:25 CET, end at Wed 2021-03-03 10:34:34 CET. --
mars 03 00:41:32 ubuntu ubiquity[59340]: grub-install : attention : Cannot read EFI Boot* variables.
mars 03 00:41:32 ubuntu ubiquity[59340]: grub-install : attention :
mars 03 00:41:32 ubuntu ubiquity[59340]: grub-install : attention : vars_get_variable: read_file(/sys/firmware/efi/vars/Boot0004-8be4df61-93ca-11d2-aa0d-00e098032b8c/r>
mars 03 00:41:32 ubuntu ubiquity[59340]: grub-install : attention : efi_get_variable: ops->get_variable failed: Erreur d'entrée/sortie.
lines 1-5/5 (END)

ubuntu@ubuntu:/target/sys/firmware/efi/vars/Boot0004-8be4df61-93ca-11d2-aa0d-00e098032b8c$ ls -ls
total 0
0 -r-------- 1 root root 4096 mars 3 10:30 attributes
0 -r-------- 1 root root 4096 mars 3 10:30 data
0 -r-------- 1 root root 4096 mars 3 10:30 guid
0 -rw------- 1 root root 4096 mars 3 10:30 raw_var
0 -r-------- 1 root root 4096 mars 3 10:30 size
ubuntu@ubuntu:/target/sys/firmware/efi/vars/Boot0004-8be4df61-93ca-11d2-aa0d-00e098032b8c$