svelte/packages/svelte/messages/compile-errors/special_elements.md

svelte_options_invalid_attribute

<svelte:options> can only receive static attributes

svelte_options_invalid_attribute_value

Valid values are %list%

svelte_options_deprecated_tag

"tag" option is deprecated — use "customElement" instead

svelte_options_invalid_tagname

Tag name must be two or more words joined by the "-" character

svelte_options_invalid_customelement

"customElement" must be a string literal defining a valid custom element name or an object of the form { tag: string; shadow?: "open" | "none"; props?: { [key: string]: { attribute?: string; reflect?: boolean; type: .. } } }

svelte_options_invalid_customelement_props

"props" must be a statically analyzable object literal of the form "{ [key: string]: { attribute?: string; reflect?: boolean; type?: "String" | "Boolean" | "Number" | "Array" | "Object" }"

svelte_options_invalid_customelement_shadow

"shadow" must be either "open" or "none"

svelte_options_unknown_attribute

<svelte:options> unknown attribute '%name%'

illegal_svelte_head_attribute

<svelte:head> cannot have attributes nor directives

invalid_svelte_fragment_attribute

<svelte:fragment> can only have a slot attribute and (optionally) a let: directive

invalid_svelte_fragment_slot

<svelte:fragment> slot attribute must have a static value

invalid_svelte_fragment_placement

<svelte:fragment> must be the direct child of a component

invalid_svelte_element_placement

<%name%> tags cannot be inside elements or blocks

duplicate_svelte_element

A component can only have one <%name%> element

invalid_self_placement

<svelte:self> components can only exist inside {#if} blocks, {#each} blocks, {#snippet} blocks or slots passed to components

missing_svelte_element_definition

<svelte:element> must have a 'this' attribute

missing_svelte_component_definition

<svelte:component> must have a 'this' attribute

invalid_svelte_element_definition

Invalid element definition — must be an {expression}

invalid_svelte_component_definition

Invalid component definition — must be an {expression}

invalid_svelte_tag

Valid <svelte:...> tag names are %list%

conflicting_slot_usage

Cannot use <slot> syntax and {@render ...} tags in the same component. Migrate towards {@render ...} tags completely.