Support XDG directories on macOS

[strega-nil]

Hiya!

I've been going around different Rust apps that I use, and trying to fix this issue, and I noticed that this crate was reasonably official, and still broken.

The directories used right now are great for GUI apps (i.e., applications that live in /Applications), but is extremely unexpected for unix/CLI style applications. It seems really unfortunate to break people's expectations like this, especially because most people just end up using confy without thinking through the implications of a very odd configuration location.

We have a few examples of applications that used to do it the dirs way, because they just did "the default" thing, and then they've had to change to be correct:

• bat
• jj-vcs

And some examples of applications that have always used XDG on macOS (or which switched from a dotfile in the home directory to XDG when XDG became a standard), including both Rust applications and applications that are from outside the Rust ecosystem:

• git
• neovim
• gcloud
• iterm2 uses both
• kitty
• tmux
• wezterm
• dust
• fd

Additionally, it looks like cargo will be switching to using XDG directories Soon (tm) - thread here

I will also point out that I don't think any macOS developers have ever complained about programs putting their configuration files in ~/.config – but quite a few have complained about configuration being in ~/Library/Application Support. I made the change for jj, and I have had like five people message me thanking me for fixing it. It is not expected for CLI application to put their configuration in ~/Library, and I would appreciate if the semi-official Rust stuff supported the correct paths.

Of course, for GUI applications, it may be the case that you want your configuration in ~/Library/Application Support – that means you'll likely want to still be able to put configuration there, but the default should almost certainly be in ~/.config, since the application that's likely to use confy is likely to be a CLI app.

[Zykino]

I don’t understand, we are using dirs exactly so they can have sane defaults that we can rely on them for. To me dirs should use the XDG env var if they exist, or a correct default, maybe with a config "graphic or command line".

Do they have a reason stated why they don’t do it that way?

[strega-nil]

@Zykino yes, they don't do it that way because they read the standard incorrectly, and are extremely stubborn that XDG directories do not belong on macOS. dirs is, unfortunately, both opinionated and wrong. Here are the links to the issue threads:

• Support for using ~/.config on Mac for command line apps dirs-dev/directories-rs#47 – this one is the most interesting and most clearly states the situation (I would point you to just how many downvotes soc, the person who maintains dirs, gets)
• Honor XDG variables on MacOS dirs-dev/dirs-rs#56
• MacOS $XDG_* dirs-dev/dirs-rs#35

The correct behavior has been implemented in etcetera

[deg4uss3r]

I have a local draft for this that I am finishing up. It's step 1 which puts xdg behind a feature flag so you can use it now.

[deg4uss3r]

I've opened #119

If one could test on linux to make sure this doesn't break between versions I'd be very appreciative, I'd like to ensure we don't regress anyone currently using a binary built on top of this without knowing it (I do plan on a 1.1 release) but would like to know what changes.