HISTFILE doesn't appear to work in ion-1.0.5 (Arch Linux)
In ~/.config/ion/initrc I placed:
source "${HOME}/.profile"
let HISTFILE="${HOME}/.histfile"
export TERM="xterm-256color"
which omniprompt > /dev/null || cargo install --git https://github.com/spease/omniprompt.git
fn PROMPT
&& omniprompt 0 || omniprompt "E"
end
This still doesn't appear to use .histfile . In the end, I replaced the default history location with a symlink and it worked. However, it'd be preferable for the config setting to work.