glanceapp/glance · error

creating theme presets: %v

Error message

creating theme presets: %v

What it means

Startup fails when newOrderedYAMLMap cannot build the built-in theme preset map. Internally that constructor errors when the keys and values slices have different lengths; since both slices are hardcoded literals in glance.go (light/dark presets), a mismatch means the source was edited inconsistently or the function was reused with mismatched slices in a fork/plugin.

Source

Thrown at internal/glance/glance.go:126

		defaultDarkTheme, ok := config.Theme.Presets.Get("default-dark")
		if ok && !config.Theme.SameAs(defaultDarkTheme) || !config.Theme.SameAs(&themeProperties{}) {
			themeKeys = append(themeKeys, "default-dark")
			themeProps = append(themeProps, &themeProperties{})
		}

		themeKeys = append(themeKeys, "default-light")
		themeProps = append(themeProps, &themeProperties{
			Light:                    true,
			BackgroundColor:          &hslColorField{240, 13, 95},
			PrimaryColor:             &hslColorField{230, 100, 30},
			NegativeColor:            &hslColorField{0, 70, 50},
			ContrastMultiplier:       1.3,
			TextSaturationMultiplier: 0.5,
		})

		themePresets, err := newOrderedYAMLMap(themeKeys, themeProps)
		if err != nil {
			return nil, fmt.Errorf("creating theme presets: %v", err)
		}
		config.Theme.Presets = *themePresets.Merge(&config.Theme.Presets)

		for key, properties := range config.Theme.Presets.Items() {
			properties.Key = key
			if err := properties.init(); err != nil {
				return nil, fmt.Errorf("initializing preset theme %s: %v", key, err)
			}
		}
	}

	config.Theme.Key = "default"
	if err := config.Theme.init(); err != nil {
		return nil, fmt.Errorf("initializing default theme: %v", err)
	}

	//
	// Init pages

View on GitHub (pinned to 91324e8de7)

Solutions

1. If you edited the preset lists, make every key in themeKeys have exactly one entry in themeProps at the same index
2. If using newOrderedYAMLMap in your own code, build both slices from a single source (one loop, or key/value pairs) so they cannot diverge
3. Diff against upstream glance to find the accidental asymmetry

Example fix

// before (fork edit gone wrong)
themeKeys = append(themeKeys, "default-light")
// forgot: themeProps = append(themeProps, &themeProperties{...})
// after
themeKeys = append(themeKeys, "default-light")
themeProps = append(themeProps, &themeProperties{Light: true})

// Guard the constructor invariant in your own code
if len(keys) != len(values) {
    return nil, fmt.Errorf("keys/values length mismatch: %d vs %d", len(keys), len(values))
}

For fork/plugin code calling newOrderedYAMLMap, validate slice lengths first; in stock glance this error indicates a source edit — fix the edit, not a runtime catch.

When it happens

Trigger: Calling newOrderedYAMLMap(themeKeys, themeProps) with len(themeKeys) != len(themeProps), or modifying the hardcoded preset lists in glance.go and adding a key without a matching properties entry.

Common situations: Fork maintainers adding a new built-in theme preset and forgetting the matching themeProperties entry; reusing newOrderedYAMLMap elsewhere with slices built by separate loops.

Related errors

• initializing preset theme %s: %v
• initializing default theme: %v
• invalid include match: %v
• decoding secret-key: %v
• secret-key must be exactly %d bytes

AI-assisted analysis of glanceapp/glance@91324e8de7 (2026-08-15). Data as JSON: /api/errors/42e8a3d9eb4c98a9. Report an issue: GitHub.