docs: Update install instructions for nushell

[Joniator]

This PR should have fixed the path issues, but the problem described in this discussion was not fixed.

The issue doesn't persist if the file is autoloaded, but the documentation currently describes the old way of importing the file with use. This updates the docs to write the autoload-way into the nu config

[Copilot]

Pull Request Overview

This PR updates the nushell installation instructions for mise to use the autoload directory instead of the manual use command approach, addressing path issues that persist with the previous method.

• Replaces multi-line installation steps with a single command that saves to the autoload directory
• Removes the manual use command approach that was causing path-related problems

[jdx]

bugbot run

[cursor]

✅ Bugbot reviewed your changes and found no bugs!

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[jdx]

@JoaquinTrinanes @atty303 @samuelallan72 @finalchild @texastoland (people that have contributed to nushell)

can any of you have a glance at this and see if it seems reasonable? I don't know enough about nushell to properly review it myself

[atty303]

Yes, this code is essentially the same as the one I use for initialization, and there is no problem with it.

# Generate vendor/autoload scripts
const vendor_autoload = $nu.data-dir | path join vendor autoload

if (which mise | is-not-empty) {
    const init_path = $vendor_autoload | path join mise.nu
    ^mise activate nu | save $init_path --force
}

[jdx]

thanks @atty303

[samuelallan72]

@jdx note that this fails if .local/share/nushell/vendor/autoload doesn't already exist (it probably doesn't by default; it wasn't created automatically for me).

Suggested change

	'^mise activate nu | save --force ($nu.data-dir | path join vendor autoload mise.nu)' | save $nu.config-path --append
	mkdir ($nu.data-dir | path join vendor autoload mise.nu)
	'^mise activate nu | save --force ($nu.data-dir | path join vendor autoload mise.nu)' | save $nu.config-path --append

[samuelallan72]

@jdx @Joniator I tested this way according to the new instructions, but it doesn't work. The generated mise.nu exports a main function - this is designed to work with the use mise.nu format. Putting the mise.nu file in the autoload directory does indeed autoload the file, but the main function is registered in nushell as literally main instead of mise.

If we want to switch to this autoload method, we'll also need to make some changes to what is output by mise activate nu.

#3592 should have fixed the path issues, but the problem described in #3555 was not fixed.

Could you comment on the related discussion with what wasn't working for you and how to reproduce it? The PR I submitted fixed the issue for me, and I haven't had trouble with use mise.nu since.

EDIT: please see following conversation at #3555 (reply in thread) . I don't think we want to switch to an autoload script; it can remain as a module, keeping the previous nushell installation instructions (ie. this PR probably should be reverted). I'll look into a fix for the prepend path issue. :)