Prefer using local over local -n

[ipetkov]

• zsh on macOS (the default shell) apparently does not support local -n and will error out if used

[Mic92]

direnv should also use bash. How do you get this sourced in zsh?

[kingarrrt]

This would break it. local -n makes a named reference used by the caller.

[bbenne10]

Using nix-direnv directly in zsh is not supported. I'm going to close this, but I think the discussion is worth continuing even so (namely "How did this get sourced in zsh?" and "If this is because of confusion over installation procedures, can we clarify installation procedures at all to help with that?")

[ipetkov]

My mistake, I had assumed it was due to using zsh but that's not the actual issue: macOS's provided version of bash itself doesn't appear to support local -n:

Without direnv enabled:

$ which bash
/bin/bash
$ bash --version
GNU bash, version 3.2.57(1)-release (arm64-apple-darwin23)
Copyright (C) 2007 Free Software Foundation, Inc.

---

I think it's still valuable to avoid using local -n to support older shells. We use direnv to activate a Nix environment which does pull in bash 5.2, but we can't do that until direnv evaluates/activates so we're stuck using whatever version macOS distributes

Could we reopen this?

[ipetkov]

This would break it. local -n makes a named reference used by the caller.

Not super familiar with this feature, is there a different way to write the implementation to not need this?

[ipetkov]

More context: I can reproduce this with direnv installed via homebrew

[bbenne10]

This is explicitly noted in the README already. We ask users to install a modern bash version into their profile. You can do this with homebrew or nix or any other packaging tool for macOS. If you're installing direnv from homebrew, is it not reasonable to also install bash from there? The version shipped with macOS is ancient and I'm afraid that this is not the only thing we'll run afoul of on a version that old.

I'll reopen if there's a change to the source branch that fixes for 3.2 without a bunch more complexity for modern bash versions, but I'm hesitant to say that we'll continue to support ancient bash versions on proprietary systems (even as a user of macOS + nix-direnv myself!)

[Mic92]

We heavily depend on bash's regex feature. Is this even part of 3.2?

[ipetkov]

Thanks for the context here! A bunch of colleagues hit this at work and I was hopeful there could be an easy solution but looks like there isn't. I'll suggest to them to install a newer version of bash