update message, add some details

Author: Rich-Harris

documentation/docs/98-reference/.generated/compile-errors.md

@@ -703,9 +703,27 @@ Cannot use explicit children snippet at the same time as implicit children conte
 ### snippet_invalid_export
 
 ```
-Cannot export snippet from a `<script module>` if it references logic or expressions inside the component
+An exported snippet can only reference things declared in a `<script module>`, or other exportable snippets
 ```
 
+It's possible to export a snippet from a `<script module>` block, but only if it doesn't reference anything defined inside a non-module-level `<script>`. For example you can't do this...
+
+```svelte
+<script module>
+	export { greeting };
+</script>
+
+<script>
+	let message = 'hello';
+</script>
+
+{#snippet greeting(name)}
+	<p>{message} {name}!</p>
+{/snippet}
+```
+
+...because `greeting` references `message`, which is defined in the second `<script>`.
+
 ### snippet_invalid_rest_parameter
 
 ```

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

@@ -140,7 +140,25 @@
 
 ## snippet_invalid_export
 
-> Cannot export snippet from a `<script module>` if it references logic or expressions inside the component
+> An exported snippet can only reference things declared in a `<script module>`, or other exportable snippets
+
+It's possible to export a snippet from a `<script module>` block, but only if it doesn't reference anything defined inside a non-module-level `<script>`. For example you can't do this...
+
+```svelte
+<script module>
+	export { greeting };
+</script>
+
+<script>
+	let message = 'hello';
+</script>
+
+{#snippet greeting(name)}
+	<p>{message} {name}!</p>
+{/snippet}
+```
+
+...because `greeting` references `message`, which is defined in the second `<script>`.
 
 ## snippet_parameter_assignment
 

packages/svelte/src/compiler/errors.js

@@ -406,12 +406,12 @@ export function runes_mode_invalid_import(node, name) {
 }
 
 /**
- * Cannot export snippet from a `<script module>` if it references logic or expressions inside the component
+ * An exported snippet can only reference things declared in a `<script module>`, or other exportable snippets
  * @param {null | number | NodeLike} node
  * @returns {never}
  */
 export function snippet_invalid_export(node) {
-	e(node, "snippet_invalid_export", "Cannot export snippet from a `<script module>` if it references logic or expressions inside the component");
+	e(node, "snippet_invalid_export", "An exported snippet can only reference things declared in a `<script module>`, or other exportable snippets");
 }
 
 /**