eval of shell-hooks command prints errors if cache has been cleared

[MatthewDolan]

The standard shell-hooks command is eval "$(test -x $HOME/bin/hermit && $HOME/bin/hermit shell-hooks --print --zsh)"
https://cs.github.com/cashapp/hermit/blob/18405e856a5c566d5e5f8d0b8b0f954ce192aec0/shell/zsh.go#L43

This command prints errors when it's run if the cache directory has been deleted.

> rm -rf ~/.cache/hermit
> eval "$(test -x $HOME/bin/hermit && $HOME/bin/hermit shell-hooks --print --zsh)"
zsh: command not found: Creating
zsh: command not found: Downloading
zsh: command not found: Hermit
zsh: command not found: Removing
zsh: command not found: Hermit
zsh: command not found: See      

This is because the shell-hooks --print command prints some extraneous information if the cache has been deleted.

> rm -rf ~/.cache/hermit
> $HOME/bin/hermit shell-hooks --print --zsh
Creating /home/codespace/.cache/hermit/pkg/hermit@stable
Downloading https://github.com/cashapp/hermit/releases/download/stable/hermit-linux-amd64.gz to /home/codespace/.cache/hermit/pkg/hermit@stable/hermit
Hermit installed as /home/codespace/.cache/hermit/pkg/hermit@stable/hermit
Removing the previous /home/codespace/bin/hermit-stable
Hermit is installed as /home/codespace/bin/hermit

change_hermit_env() {
...

I have a bit of a hacky solution which is to run hermit version > /dev/null first which forces the install before running the shell-hooks command.

eval "$(test -x $HOME/bin/hermit &&  $HOME/bin/hermit version > /dev/null && $HOME/bin/hermit shell-hooks --print --zsh)"

It might worth making a less hacky / more permanent fix (there are a few options I can think of but I am not confident enough on which is the right fix).

(For context, the reason I came across this was that I recently updates my dotfiles install.sh to automatically install hermit.

MatthewDolan/dotfiles@e472587

Mostly, it worked perfectly. Except that there is a bug when hermit tries to print shell-hooks if the cache has been cleared.)