Bad practice to configure Fish without universal variables?

[trallnag]

Is there a big disadvantage (for example performance-wise) for configuring Fish login shells with commands like

set -x EDITOR nano
set -x VISUAL nano
set -x PAGER less

that are executed every time a login shell occurs instead of running

set -U EDITOR nano
set -U VISUAL nano
set -U PAGER less

once?

Why do I want to do it like this? It is more similar to how things work in Bash and Zsh and it fits better into my Ansible Playbooks I use to manage my environments.

[faho]

These aren't the same thing.

set -x EDITOR nano creates a variable and marks it to be exported. That means it will be passed to external processes, so if you do git commit it will know your $EDITOR and will run nano to edit your commit message. In this case, because your variable doesn't already exist, it will be made global. It's good practice to spell this out like set -gx EDITOR nano and make it global and exported explicitly.

set -U EDITOR nano makes a universal variable $EDITOR and sets it to nano. It won't be exported unless it's set to be exported somewhere else. And exported universal variables can sometimes be annoyingly sticky, see https://fishshell.com/docs/current/faq.html#why-doesn-t-set-ux-exported-universal-variables-seem-to-work.

That being said:

Is there a big disadvantage (for example performance-wise) for configuring Fish login shells with commands like

No. It's fine. Setting a variable is quite fast. If you did have a performance problem you could measure it (for example with fish --profile-startup), but I can almost guarantee you it'll be somewhere else.

[trallnag]

alright, thanks!