4 errors when building custom GNU Grub installation packages

"[email protected]" <[email protected]> Wed, 1 Jan 2025 07:40:49 GMT
Newsgroups gmane.comp.boot-loaders.grub.bugs
Message-ID <[email protected]>
Hello GNU Grub bootloader,

I have 4 errors when I tried building custom GNU Grub installation packages.
I followed two pages for instructions.
https://askubuntu.com/questions/496549/error-you-must-put-some-source-uris-in-your-sources-list
https://askubuntu.com/posts/857433/revisions
https://askubuntu.com/questions/357186/how-to-change-the-header-title-and-help-message-in-grub-menu
https://askubuntu.com/posts/361185/revisions

Maybe there was a limit in changing the header/footer message string values? For instance, I tried putting a comment code in the header string value. I didn't get clarification about limitations, but I should be keen about these facts.

4 errors
FAIL: ext234_test
FAIL: squashfs_test
FAIL: fat_test
FAIL: exfat_test

mkfs.vfat: Labels with characters *?.,;:/\|+=<>[]" are not allowed

Maybe you can let me know the source of these 4 errors?

--
Sincerely,
[email protected]