macOS: cache data written to ~/.cache instead of ~/Library/Caches, XDG var ignored

[rycli]

Issue Description

Since 1.4.0, Ghostty incorrectly uses/checks XDG_CACHE_HOME that stores the Sentry database. When the variable is not set, it writes to ~/.cache/ghostty/sentry. This ends up being the default scenario when Ghostty is opened from Spotlight/Dock/Finder. When the variable is set, it ignores it and writes to ~/Library/Caches/com.mitchellh.ghostty/sentry.

This seems to be caused by the logic at https://github.com/ghostty-org/ghostty/blob/main/src/crash/sentry.zig#L192 which seems to result in the opposite of what the comment above it describes..

Expected Behavior

Logic prior to 1.4:

• XDG_CACHE_HOME missing or empty: ~/Library/Caches/com.mitchellh.ghostty/sentry
• XDG_CACHE_HOME set: $XDG_CACHE_HOME/ghostty/sentry

Actual Behavior

• XDG_CACHE_HOME missing or empty: ~/.cache/ghostty/sentry
• XDG_CACHE_HOME set: ~/Library/Caches/com.mitchellh.ghostty/sentry

Reproduction Steps

1. Check that launchctl getenv XDG_CACHE_HOME shows empty
2. Open Ghostty
3. ls ~/.cache

Ghostty Logs

No response

Ghostty Version

Ghostty 1.4.0

Version
  - version: 1.4.0
  - channel: stable
Build Config
  - Zig version   : 0.17.0
  - build mode    : .fast
  - app runtime   : .none
  - font engine   : .coretext
  - renderer      : renderer.generic.Renderer(renderer.Metal)
  - libxev        : kqueue

OS Version Information

macOS 27.2 (26B123)

(Linux only) Display Server

None

(Linux only) Desktop Environment/Window Manager

No response

Minimal Ghostty Configuration

n/a

Additional Relevant Configuration

No response

I acknowledge that:

• I have reviewed the FAQ and confirm that my issue is NOT among them.
• I have searched the Ghostty documentation and confirm there doesn't exist a configuration option that solves my issue.
• I have searched the Ghostty repository (both open and closed Discussions and Issues) and confirm this is not a duplicate of an existing issue or discussion.
• I have checked the "Preview" tab on all text fields to ensure that everything looks right, and have wrapped all configuration and code in code blocks with a group of three backticks (```) on separate lines.

[18w]

Hi @rycli, good catch!

I checked it, you are right. It got inverted in 15c50c1 ("crash: do not use global state", #13567), that's why 1.3.x is fine and 1.4.0 isn't.

Before that commit it was:

if (global.environ().containsUnemptyConstant("XDG_CACHE_HOME")) break :macos;

so set and non-empty meant use XDG. Now it is:

const xdg_cache_home = environ_map.get("XDG_CACHE_HOME") orelse break :macos;
if (xdg_cache_home.len > 0) {
    return try internal_os.macos.cacheDir(alloc, "sentry");
}

which picks ~/Library/Caches only when the var is set, and falls through to internal_os.xdg.cache otherwise. Exactly the swap you see. Should be something like:

if (comptime builtin.target.os.tag == .macos) macos: {
    if (environ_map.get("XDG_CACHE_HOME")) |v| {
        if (v.len > 0) break :macos;
    }
    return try internal_os.macos.cacheDir(alloc, "sentry");
}

Until then you can delete ~/.cache/ghostty/sentry, it's only the crash report database.

Might be worth turning this into an issue/PR since the fix is small.