If you've recently updated to Ghostty 1.2 and found that your carefully configured themes are no longer loading, you're not alone. This update introduced several changes that can break existing theme configurations, leaving users with default terminal appearances or error messages.

What's happening?

The Ghostty 1.2 update brings significant changes to how themes are handled, which can cause existing configurations to break in several ways:

1. Theme naming format has changed

The update includes a significant change to how theme names are formatted in the configuration. Theme names have changed from kebab-case to title case with proper capitalization:

Before (Ghostty 1.1 and earlier):

theme = dark:catppuccin-frappe,light:catppuccin-latte

After (Ghostty 1.2):

theme = dark: Catppuccin Frappe,light: Catppuccin Latte

This means if your configuration still uses the old kebab-case format, Ghostty won't be able to find the themes.

2. Font features have changed

The dlig font feature is now disabled by default, which can affect ligatures that were previously working in your themes.

How to fix it

Check what themes are available

First, see what themes are currently available in your Ghostty installation:

ghostty +list-themes

This will show you all the themes that Ghostty can find, including any that may have been renamed.

Update your configuration

If your theme was renamed or the naming format changed, update your Ghostty configuration file (typically at ~/.config/ghostty/config) with the new theme name format:

For bundled themes, update from kebab-case to title case:

# Old format
theme = dark:catppuccin-frappe,light:catppuccin-latte

# New format
theme = dark: Catppuccin Frappe,light: Catppuccin Latte

For custom themes, use the full path:

theme = ~/.config/ghostty/themes/your-custom-theme.conf

Alternative: Inline themes in configuration

You can also define your theme directly in your Ghostty configuration file. While this might be less convenient for managing multiple themes, it ensures your theme settings survive updates:

[theme]
# Your theme configuration here
foreground = #ffffff
background = #000000
# ... other theme properties

Re-enable font features if needed

If you were using ligatures that stopped working, you can re-enable the dlig font feature in your configuration:

font-features = +dlig

Prevention for future updates

To avoid issues in future updates:

1. Keep backups of your theme files and configuration
2. Check release notes before updating to see if there are breaking changes
3. Test your configuration after updates to ensure everything still works

The bottom line

While the Ghostty 1.2 update brings improvements and new features, the theme handling changes can be disruptive. The main issue is the change in theme naming format from kebab-case to title case, which requires updating your configuration to use the new format.

If you're still having issues after trying these solutions, check the Ghostty documentation or the GitHub repository for more specific guidance.

Have you encountered this issue?