Opinion about XDG support by the Clojure tools (deps, cli)

[jgomo3]

Clojure should not rely only on the XDG_CONFIG_HOME environment variable to follow the XDG standard.

In an XDG System, XDG_CONFIG_HOME exists to allow users to override the default which is ~/.config.[1]

Defining XDG_CONFIG_HOME in my XDG system as ~/.config is redundant, but I’m forced to do it by Clojure if I want to keep all my configuration files in ~/.config.

The order for “User - cross-project configuration (typically tools)” according to the Clojure reference is:

1. If $CLJ_CONFIG is set, then use $CLJ_CONFIG (explicit override)
2. If $XDG_CONFIG_HOME is set, then use $XDG_CONFIG_HOME/clojure (Freedesktop conventions)
3. Else use $HOME/.clojure (most common)

But I think the tools should find another way to determine if the System is an XDG System. Let’s say it exists, step 2 should be something like:

2. If an XDG System, use $XDG_CONFIG_HOME if set or $HOME/.config/clojure

That predicate “is an XDG System” could be implemented (redundantly) as: Is $XDG_CONFIG_HOME set or $HOME/.config exists?.

So another more specific way to implement 2:

2. XDG_CONFIG_HOME if set or $HOME/.config/clojure if exists.

And if it is a clean system, with no preexisting ~/.clojure nor ~/.config/clojure, the creation of .config/clojure should take precedence over .clojure if Clojure can tell if the System is an XDG System.

End of my OPINION (just highlighting it is just an Opinion). ← Opinion

[1] “If $XDG_CONFIG_HOME is either not set or empty, a default equal to $HOME/.config should be used” - Environment variables

[alexmiller]

For future reference, requests or problems with the Clojure CLI should be filed at https://ask.clojure.org where they can be triaged into tickets. I might see things here, but also, I might not.

Can you point to some doc references for XDG that would definitely say how to determine if it is an XDG system?

[jgomo3]

@alexmiller

For future reference, requests or problems with the Clojure CLI should be filed at https://ask.clojure.org where they can be triaged into tickets. I might see things here, but also, I might not.

Noted, thanks.

@alexmiller

Can you point to some doc references for XDG that would definitely say how to determine if it is an XDG system?

Sure. The XDG Base Directory Specification should be that document (version 0.8 today).

I think there is no an API or standard way to ask a System if it is an XDG system because it’s a chicken-egg problem. What I’ve seen it is mostly done is checking for the $XDG_CONFIG_HOME value and if not, checking for the $HOME/.config folder; failing that “means” not XDG.

The tool published in the Freedesktop site for scripting is a Python tool called pyxdg, and it has a module dedicated to the Base Directory specification. You can see specifically how they define the xdg_config_home as:

xdg_config_home = os.environ.get('XDG_CONFIG_HOME') or \
            os.path.join(_home, '.config')

TLDR: The XDG Base Directory Specification should be that document.