fix: neoforge not existing for 26.1 breaking vers picker (#5674)

* fix: neoforge for 26.1 -> other vers being picked not existing causing version picker to break

* fix: lint

packages/ui/src/components/flows/creation-flow-modal/components/CustomSetupStage.vue

@@ -254,6 +254,14 @@ async function fetchLoaderManifest(loader: string) {
 	let apiLoader = loader
 	if (apiLoader === 'neoforge') apiLoader = 'neo'
 
+	debug(
+		'fetchLoaderManifest:',
+		loader,
+		'apiLoader:',
+		apiLoader,
+		'cached:',
+		!!loaderVersionsCache.value[apiLoader],
+	)
 	if (loaderVersionsCache.value[apiLoader]) return
 
 	try {
@@ -262,7 +270,9 @@ async function fetchLoaderManifest(loader: string) {
 			gameVersions: { id: string; loaders: LoaderVersionEntry[] }[]
 		}
 		loaderVersionsCache.value[apiLoader] = data.gameVersions
-	} catch {
+		debug('fetchLoaderManifest: loaded', apiLoader, 'gameVersions:', data.gameVersions.length)
+	} catch (e) {
+		debug('fetchLoaderManifest: FAILED', apiLoader, e)
 		loaderVersionsCache.value[apiLoader] = []
 	}
 }
@@ -319,13 +329,32 @@ function getLoaderVersionsForGameVersion(
 	if (apiLoader === 'neoforge') apiLoader = 'neo'
 
 	const manifest = loaderVersionsCache.value[apiLoader]
+	debug('getLoaderVersionsForGameVersion:', {
+		loader,
+		apiLoader,
+		gameVersion,
+		hasManifest: !!manifest,
+		manifestLength: manifest?.length,
+	})
 	if (!manifest) return []
 
 	// Some loaders (e.g. Fabric) list all versions under a placeholder entry
 	const placeholder = manifest.find((x) => x.id === '${modrinth.gameVersion}')
-	if (placeholder) return placeholder.loaders
+	if (placeholder) {
+		debug(
+			'getLoaderVersionsForGameVersion: using placeholder, loaders:',
+			placeholder.loaders.length,
+		)
+		return placeholder.loaders
+	}
 
 	const entry = manifest.find((x) => x.id === gameVersion)
+	debug(
+		'getLoaderVersionsForGameVersion: entry for',
+		gameVersion,
+		':',
+		entry ? entry.loaders.length + ' loaders' : 'NOT FOUND',
+	)
 	return entry?.loaders ?? []
 }
 
@@ -348,9 +377,12 @@ watch(
 )
 
 // Watch loader + game version to resolve loader versions
+let loaderVersionWatchId = 0
 watch(
 	[() => selectedLoader.value, () => selectedGameVersion.value],
 	async ([loader, gameVersion]) => {
+		const watchId = ++loaderVersionWatchId
+		debug('watch [loader, gameVersion] fired:', { loader, gameVersion, watchId })
 		loaderVersionsData.value = []
 		selectedLoaderVersion.value = null
 
@@ -360,8 +392,8 @@ watch(
 
 		if (loader === 'paper') {
 			await fetchPaperVersions(gameVersion)
+			if (watchId !== loaderVersionWatchId) return
 			loaderVersionsLoading.value = false
-			// Auto-select latest build
 			const builds = paperVersions.value[gameVersion]
 			if (builds?.length) {
 				selectedLoaderVersion.value = `${builds[0]}`
@@ -371,8 +403,8 @@ watch(
 
 		if (loader === 'purpur') {
 			await fetchPurpurVersions(gameVersion)
+			if (watchId !== loaderVersionWatchId) return
 			loaderVersionsLoading.value = false
-			// Auto-select latest build
 			const builds = purpurVersions.value[gameVersion]
 			if (builds?.length) {
 				selectedLoaderVersion.value = builds[0]
@@ -381,7 +413,18 @@ watch(
 		}
 
 		await fetchLoaderManifest(loader)
+		if (watchId !== loaderVersionWatchId) {
+			debug('watch [loader, gameVersion]: stale execution, skipping', {
+				watchId,
+				current: loaderVersionWatchId,
+			})
+			return
+		}
 		loaderVersionsData.value = getLoaderVersionsForGameVersion(loader, gameVersion)
+		debug(
+			'watch [loader, gameVersion]: loaderVersionsData set, count:',
+			loaderVersionsData.value.length,
+		)
 		loaderVersionsLoading.value = false
 
 		// Auto-select based on loaderVersionType
@@ -395,6 +438,16 @@ watch(
 )
 
 function autoSelectLoaderVersion() {
+	debug(
+		'autoSelectLoaderVersion: type:',
+		loaderVersionType.value,
+		'dataCount:',
+		loaderVersionsData.value.length,
+		'stableCount:',
+		loaderVersionsData.value.filter((v) => v.stable).length,
+		'first:',
+		loaderVersionsData.value[0]?.id,
+	)
 	if (loaderVersionType.value === 'stable') {
 		const stable = loaderVersionsData.value.find((v) => v.stable)
 		selectedLoaderVersion.value = stable?.id ?? loaderVersionsData.value[0]?.id ?? null
@@ -403,7 +456,7 @@ function autoSelectLoaderVersion() {
 	} else if (loaderVersionType.value === 'other' && !selectedLoaderVersion.value) {
 		selectedLoaderVersion.value = loaderVersionsData.value[0]?.id ?? null
 	}
-	debug('autoSelectLoaderVersion:', selectedLoaderVersion.value, 'type:', loaderVersionType.value)
+	debug('autoSelectLoaderVersion: result:', selectedLoaderVersion.value)
 }
 
 const loaderVersionOptions = computed<ComboboxOption<string>[]>(() => {