Is there a guide to setting up a build host?

[dekeonus]

The archlinuxarm site only talks about using distcc for cross compiling;- If I have to build by using distcc, I may as well stick gentoo on my pinephone / pinetab - all my distcc hosts are gentoo already.

What I'm looking for is guidance on creating a chroot / qemu build host specifically on a gentoo x86_64 host.
What parts of a base arch system would be needed?

[ArenM]

What parts of a base arch system would be needed?

All of them, iiuc makepkg doesn't have any concept of cross compiling, your best bet is to download an arch/arm rootfs and chroot it using qemu. You can then makepkg in the chroot to build packages.

I use these scripts to manage that for me, but they've been unmaintined for a while, so ymmv.

[dekeonus]

TY! it was the information from https://nerdstuff.org/posts/2020/2020-003_simplest_way_to_create_an_arm_chroot/ that I was missing