I broke my daily driver EOS Cinnamon install–one that I’ve had going since December. I know what I did wrong and it’s embarrassing, so I won’t get into that.
I did a fresh install of the latest iso. On reboot, my Windows option was absent from the grub menu. “No biggie” I thought. I went through the now familiar process of adding the GRUB_DISABLE_OS_PROBER=false line and running grub-mkconfig.
Still no Windows. I booted Windows from BIOS and it was fine. I examined the contents of the EFI partition and Windows entries were intact. I also checked efibootmgr and nothing seemed amiss. I did my usual thing and read the wiki last. I didn’t see any obvious mistakes on my part. Google suggested I start from scratch and use NTFS-3G. Fat chance.
Just for the helluvit I checked to see if I had the latest version of os-prober. To my chagrin, I found that os-prober was not installed at all. Feeling stupid for pissing away an hour troubleshooting a missing package, I installed 'prober and ran grub-mkconfig again.
You could also just manually add the entry to grub and not rely on prober. The Windows boot files usually sit in the same place so just pointing the entry to the right spot and label it what you want then you never have to worry about it.
I had to deal with grub + windows issues someone had a month or 2 ago like this with and just directed them to manually putting in a boot entry for windows
TBH thats not much of a reason to reinvent the wheel and is a strawman at best. If you have trouble with prober you can write a proper grub entry once and never have to deal with it and you save even more time.
You save time not duplicating work which is more time consuming than making a single grub entry which for Windows (except for maybe upgrading to 11 or reinstall) shouldnt need to change.