(SNIP)
- you have to download the linux-headers package for the Linux-Kernel
version used in the ISO
pacman -S linux-headers will do this, yes.
- there might be some point where the most current version of
bcachefs-dkms will not compile due to breaking changes in the kernel
what do mean? DKMS builds against the installed kernel(s). in ArchISO's case, the ISO's kernel if you're in the ISO runtime, or the target's installed version if you're chrooted into it.
realistically you need to do both if you're putting / on bcachefs, of course.
unless the target install and ISO kernel version are the same, in which case you technically can just do it for the ISO runtime and copy over the modules to the target.
and if you're not putting / on bcachefs, just do it post-install. no bog deal.
- same goes for older ISO images one might want to use because there
is currently no way to get current ISO
1. Arch is a rolling distro. what one "might want" to use is not supported if it's not current stable.
2. but also see above re: DKMS- you're more liable to run into chrooting/glibc issues or the like before you run into DKMS issues because of an older ISO.
3. but also also, this shouldn't matter either.[0][1](etc.)
- need to find a working bcachefs version for the current kernel version
see above re: DKMS, but assuming your ISO is somehow THAT old that the normal path doesn't work, see the ALA.[2]
[0] https://wiki.archlinux.org/title/Install_Arch_Linux_from_existing_Linux
[1] https://wiki.archlinux.org/title/Preboot_Execution_Environment (Specifically section 1.3 et. al.)
[2] https://wiki.archlinux.org/title/Arch_Linux_Archive
