Boot repair error

[marcotx]

Ok, so to add a boot stanza I have to insert it in /etc/grub.d/40_custom file.
But to modify a boot stanza what file must I edit?

[oldfred]

If Arch updates its own boot stanza, you can copy it again with the newer boot stanza into 40_custom.

Usually just the kernel version and you can just edit that also in 40_custom rather than copy entire stanza.
Update:
Looked again at Arch boot stanza and it does not seem to show version numbers, so perhaps updates not required. But then you may need some of the other boot stanzas it has as ways to boot backup or repair? Do not know about Arch and how it works.