My zsh has been a little slow to start for a while. Never enough to be a significant bother, but always something I’ve been meaning to get around to. Thorsten Ball had a great writeup about this here. Maybe I’ve had weights in my shoes for too long!

Recently I’ve been messing with the atuin init command - this is ran at shell startup. I want to ensure it’s fast, and we don’t cause slow shells for anyone.

What I did:

  1. Whack zmodload zsh/zprof at the top of my .zshrc
  2. zprof at the bottom of the same file

Upon opening a new shell, I get a nice table showing where zsh is spending time

It’s pretty obvious that nvm is to blame here! With a bit of Googling, it seems like I’m among the last to figure this out. Oops.

Fixing it

I do use nvm reasonably often, so let’s fix it

Lazy loading

zsh-lazyload allows you to lazy load commands! That way I only pay the slow nvm penalty when I’m actually using nvm. Not bad.

Install the plugin as per the readme (I used zplug), and then

lazyload nvm -- 'source ~/.nvm/'

in my .zshrc. Good to go!


There are a number of other options nowadays. I’ve been debating using asdf or mise, but haven’t gotten around to figuring out which works best for me.