pkgusers/pkggroups + install -o/-g doesn't stick in /var
https://git.sr.ht/~sircmpwn/sr.ht-apkbuilds/tree/master/item/sr.ht/sr.ht-uacme/APKBUILD#L43
This does not seem to work; I have to add a post-install to force the desired user/group. The tarball looks right, though, may be an apk-tools issue?