show the real backup error when bulk snapshot deletion fails

src/lib/components/BulkDeleteErrorDialog.svelte

@@ -0,0 +1,37 @@
+<script lang="ts">
+	import * as Dialog from '$lib/components/ui/dialog';
+	import { Button } from '$lib/components/ui/button';
+	import { AlertTriangle } from 'lucide-svelte';
+
+	interface Props {
+		open: boolean;
+		/** Raw restic stderr for the failed batch (shown verbatim). */
+		error: string;
+		/** How many snapshots were still deleted before the failure. */
+		deleted?: number;
+	}
+	let { open = $bindable(), error, deleted = 0 }: Props = $props();
+</script>
+
+<Dialog.Root bind:open>
+	<Dialog.Content class="max-w-2xl">
+		<Dialog.Header>
+			<Dialog.Title class="flex items-center gap-2 text-destructive">
+				<AlertTriangle class="h-5 w-5" />
+				Snapshots could not be deleted
+			</Dialog.Title>
+		</Dialog.Header>
+		{#if deleted > 0}
+			<p class="text-sm text-muted-foreground">
+				Deleted {deleted} snapshot{deleted === 1 ? '' : 's'}, but the rest failed. The backup
+				tool reported:
+			</p>
+		{:else}
+			<p class="text-sm text-muted-foreground">The backup tool reported:</p>
+		{/if}
+		<pre class="max-h-[50vh] overflow-auto rounded-md bg-muted p-3 text-xs whitespace-pre-wrap break-words font-mono">{error}</pre>
+		<Dialog.Footer>
+			<Button onclick={() => (open = false)}>OK</Button>
+		</Dialog.Footer>
+	</Dialog.Content>
+</Dialog.Root>

src/lib/utils/backup.ts

@@ -458,6 +458,9 @@ export interface BulkDeleteResult {
 	skipped: number;
 	/** true if any destination's batch call returned a non-2xx. */
 	failed: boolean;
+	/** Raw restic error from the first failing destination (repo locked, timeout, etc.),
+	 * surfaced verbatim so the user sees the real reason instead of a generic message. */
+	error?: string;
 }
 
 /**
@@ -469,7 +472,7 @@ export interface BulkDeleteResult {
 export async function bulkDeleteSnapshots(
 	targets: { id: string; _destinationId: number }[]
 ): Promise<BulkDeleteResult> {
-	let deleted = 0, skipped = 0, failed = false;
+	let deleted = 0, skipped = 0, failed = false, error: string | undefined;
 	for (const { destinationId, snapshotIds } of groupSnapshotIdsByDestination(targets)) {
 		try {
 			const res = await fetch('/api/backup/snapshots/batch-delete', {
@@ -480,17 +483,34 @@ export async function bulkDeleteSnapshots(
 			const data = await res.json().catch(() => ({}));
 			deleted += data.deleted?.length ?? 0;
 			if (res.ok) skipped += data.skipped?.length ?? 0;
-			else failed = true;
+			else {
+				failed = true;
+				if (!error && data.error) error = String(data.error);
+			}
 		} catch {
 			failed = true;
 		}
 	}
-	return { deleted, skipped, failed };
+	return { deleted, skipped, failed, error };
+}
+
+/**
+ * A hard restic failure that warrants the full-error dialog (repo locked, timeout,
+ * etc.) rather than a toast. Returns the raw restic error and how many were still
+ * deleted, or null when there is no such failure (toast handles success/skipped).
+ * A `failed` with no `error` (e.g. a thrown fetch) also returns null - nothing
+ * verbatim to show - so the caller falls back to the toast.
+ */
+export function bulkDeleteFailure(r: BulkDeleteResult): { error: string; deleted: number } | null {
+	if (r.failed && r.error) return { error: r.error, deleted: r.deleted };
+	return null;
 }
 
 /**
  * Consistent toast wording for a bulk-delete result, shared by every snapshot list.
  * Returns { type, message } so each caller fires its own toast (import stays local).
+ * A hard restic failure with a verbatim error is handled by the caller via
+ * bulkDeleteFailure + the error dialog, not here.
  */
 export function bulkDeleteToast(r: BulkDeleteResult): { type: 'success' | 'error'; message: string } {
 	if (r.failed) return { type: 'error', message: r.deleted > 0 ? `Deleted ${r.deleted}, but some snapshots could not be deleted` : 'Snapshots could not be deleted' };

src/routes/backups/+page.svelte

@@ -26,9 +26,10 @@
 	import { formatDateTime, formatRelativeTime } from '$lib/stores/settings';
 	import { currentEnvironment } from '$lib/stores/environment';
 	import { watchJob, readJobResponse } from '$lib/utils/sse-fetch';
-	import { getRepoTypeIcon, formatCron, retentionSummary, classifyJobResult, tagLogLine, bulkDeleteSnapshots, bulkDeleteToast } from '$lib/utils/backup';
+	import { getRepoTypeIcon, formatCron, retentionSummary, classifyJobResult, tagLogLine, bulkDeleteSnapshots, bulkDeleteToast, bulkDeleteFailure } from '$lib/utils/backup';
 	import { Checkbox } from '$lib/components/ui/checkbox';
 	import BulkDeleteSnapshotsDialog from '$lib/components/BulkDeleteSnapshotsDialog.svelte';
+	import BulkDeleteErrorDialog from '$lib/components/BulkDeleteErrorDialog.svelte';
 	import SnapshotBrowser from '../containers/SnapshotBrowser.svelte';
 	import RestoreModal from '../containers/RestoreModal.svelte';
 	import BackupLogModal from './BackupLogModal.svelte';
@@ -113,6 +114,9 @@
 	let bulkDialogOpen = $state(false);
 	let bulkDeleting = $state(false);
 	let bulkConfig = $state<BackupConfig | null>(null);
+	let bulkDeleteErrorOpen = $state(false);
+	let bulkDeleteError = $state('');
+	let bulkDeleteErrorDeleted = $state(0);
 	// Snapshots of a config, normalized to {id, _destinationId} for the shared helper.
 	function configSelectedTargets(config: BackupConfig) {
 		return (snapshotsMap.get(config.key) || [])
@@ -139,8 +143,15 @@
 		bulkDeleting = true;
 		try {
 			const result = await bulkDeleteSnapshots(configSelectedTargets(config));
-			const t = bulkDeleteToast(result);
+			const failure = bulkDeleteFailure(result);
-			toast[t.type](t.message);
+			if (failure) {
+				bulkDeleteError = failure.error;
+				bulkDeleteErrorDeleted = failure.deleted;
+				bulkDeleteErrorOpen = true;
+			} else {
+				const t = bulkDeleteToast(result);
+				toast[t.type](t.message);
+			}
 			selectedSnapshots = new Set();
 			await loadSnapshots(config);
 			const loaded = snapshotsMap.get(config.key);
@@ -1146,6 +1157,7 @@
 </div>
 
 <BulkDeleteSnapshotsDialog bind:open={bulkDialogOpen} count={bulkConfig ? configSelectedTargets(bulkConfig).length : 0} busy={bulkDeleting} onConfirm={bulkDeleteConfig} />
+<BulkDeleteErrorDialog bind:open={bulkDeleteErrorOpen} error={bulkDeleteError} deleted={bulkDeleteErrorDeleted} />
 
 <SnapshotBrowser
 	bind:open={showBrowser}

src/routes/containers/SnapshotsPanel.svelte

@@ -8,8 +8,9 @@
 	import { formatDateTime, formatRelativeTime } from '$lib/stores/settings';
 	import { formatBytes } from '$lib/utils/format';
 	import { readJobResponse } from '$lib/utils/sse-fetch';
-	import { getRepoTypeIcon, selectOwnSnapshotsFromDestination, bulkDeleteSnapshots, bulkDeleteToast } from '$lib/utils/backup';
+	import { getRepoTypeIcon, selectOwnSnapshotsFromDestination, bulkDeleteSnapshots, bulkDeleteToast, bulkDeleteFailure } from '$lib/utils/backup';
 	import BulkDeleteSnapshotsDialog from '$lib/components/BulkDeleteSnapshotsDialog.svelte';
+	import BulkDeleteErrorDialog from '$lib/components/BulkDeleteErrorDialog.svelte';
 	import SnapshotBrowser from './SnapshotBrowser.svelte';
 	import RestoreModal from './RestoreModal.svelte';
 	import SnapshotDiffModal from '../backups/SnapshotDiffModal.svelte';
@@ -57,6 +58,9 @@
 	let bulkDeleting = $state(false);
 	let bulkDialogOpen = $state(false);
 	let bulkScope = $state<'selected' | 'all'>('selected');
+	let bulkDeleteErrorOpen = $state(false);
+	let bulkDeleteError = $state('');
+	let bulkDeleteErrorDeleted = $state(0);
 	// snapshotId → { filesNew, filesChanged, dataAdded } from schedule executions.
 	let stats = $state<Map<string, { filesNew: number; filesChanged: number; dataAdded: number }>>(new Map());
 
@@ -251,8 +255,15 @@
 		bulkDeleting = true;
 		try {
 			const result = await bulkDeleteSnapshots(targets);
-			const t = bulkDeleteToast(result);
+			const failure = bulkDeleteFailure(result);
-			toast[t.type](t.message);
+			if (failure) {
+				bulkDeleteError = failure.error;
+				bulkDeleteErrorDeleted = failure.deleted;
+				bulkDeleteErrorOpen = true;
+			} else {
+				const t = bulkDeleteToast(result);
+				toast[t.type](t.message);
+			}
 			selectedSnapshots = new Set();
 			await loadSnapshots();
 		} finally {
@@ -411,6 +422,7 @@
 {/if}
 
 <BulkDeleteSnapshotsDialog bind:open={bulkDialogOpen} count={bulkCount} busy={bulkDeleting} onConfirm={() => bulkDelete(bulkScope)} />
+<BulkDeleteErrorDialog bind:open={bulkDeleteErrorOpen} error={bulkDeleteError} deleted={bulkDeleteErrorDeleted} />
 
 <SnapshotBrowser
 	bind:open={showBrowser}

src/routes/settings/backups/BackupsTab.svelte

@@ -16,8 +16,9 @@
 	import { FolderOpen, Box, Layers, FileStack, Camera, ChevronRight, ChevronDown } from 'lucide-svelte';
 	import { formatBytes } from '$lib/utils/format';
 	import { Checkbox } from '$lib/components/ui/checkbox';
-	import { bulkDeleteSnapshots, bulkDeleteToast } from '$lib/utils/backup';
+	import { bulkDeleteSnapshots, bulkDeleteToast, bulkDeleteFailure } from '$lib/utils/backup';
 	import BulkDeleteSnapshotsDialog from '$lib/components/BulkDeleteSnapshotsDialog.svelte';
+	import BulkDeleteErrorDialog from '$lib/components/BulkDeleteErrorDialog.svelte';
 	import EnvironmentIcon from '$lib/components/EnvironmentIcon.svelte';
 	import { LoadingState } from '$lib/components/ui/loading-state';
 	import { getRepoTypeIcon, getRepoTypeLabel } from '$lib/utils/backup';
@@ -290,6 +291,9 @@
 	let selectedSnapshots = $state<Set<string>>(new Set());
 	let bulkDialogOpen = $state(false);
 	let bulkDeleting = $state(false);
+	let bulkDeleteErrorOpen = $state(false);
+	let bulkDeleteError = $state('');
+	let bulkDeleteErrorDeleted = $state(0);
 	function toggleSnapshotSel(id: string) {
 		const next = new Set(selectedSnapshots);
 		if (next.has(id)) next.delete(id); else next.add(id);
@@ -310,8 +314,15 @@
 		bulkDeleting = true;
 		try {
 			const result = await bulkDeleteSnapshots(targets);
-			const t = bulkDeleteToast(result);
+			const failure = bulkDeleteFailure(result);
-			toast[t.type](t.message);
+			if (failure) {
+				bulkDeleteError = failure.error;
+				bulkDeleteErrorDeleted = failure.deleted;
+				bulkDeleteErrorOpen = true;
+			} else {
+				const t = bulkDeleteToast(result);
+				toast[t.type](t.message);
+			}
 			selectedSnapshots = new Set();
 			const dest = destinations.find((d) => d.id === browseDestId);
 			if (dest) await browseDestination(dest);
@@ -933,6 +944,7 @@
 </Dialog.Root>
 
 <BulkDeleteSnapshotsDialog bind:open={bulkDialogOpen} count={browseSelectedCount} busy={bulkDeleting} onConfirm={bulkDeleteBrowsed} />
+<BulkDeleteErrorDialog bind:open={bulkDeleteErrorOpen} error={bulkDeleteError} deleted={bulkDeleteErrorDeleted} />
 
 <SnapshotBrowser
 	bind:open={snapshotBrowseOpen}

tests/group-snapshots-by-destination.test.ts

@@ -1,5 +1,5 @@
 import { describe, it, expect, afterEach } from 'bun:test';
-import { groupSnapshotIdsByDestination, bulkDeleteSnapshots, bulkDeleteToast } from '../src/lib/utils/backup';
+import { groupSnapshotIdsByDestination, bulkDeleteSnapshots, bulkDeleteToast, bulkDeleteFailure } from '../src/lib/utils/backup';
 
 const snap = (id: string, dest: number) => ({ id, _destinationId: dest });
 
@@ -96,4 +96,29 @@ describe('bulkDeleteSnapshots', () => {
 		expect(r.failed).toBe(true);
 		expect(r.deleted).toBe(1);
 	});
+
+	it('carries the raw restic error from the first failing repo', async () => {
+		globalThis.fetch = (async (_url: string, init: any) => {
+			const body = JSON.parse(init.body);
+			if (body.destinationId === 2) return { ok: false, json: async () => ({ deleted: [], error: 'repository is already locked\ncontext canceled' }) } as any;
+			return { ok: true, json: async () => ({ deleted: ['a'], skipped: [] }) } as any;
+		}) as any;
+		const r = await bulkDeleteSnapshots([snap('a', 1), snap('b', 2)]);
+		expect(r.failed).toBe(true);
+		expect(r.error).toBe('repository is already locked\ncontext canceled');
+	});
+});
+
+describe('bulkDeleteFailure', () => {
+	it('returns the raw error and deleted count on a hard failure', () => {
+		expect(bulkDeleteFailure({ deleted: 1, skipped: 0, failed: true, error: 'repo locked' }))
+			.toEqual({ error: 'repo locked', deleted: 1 });
+	});
+	it('is null when nothing failed (toast handles success/skipped)', () => {
+		expect(bulkDeleteFailure({ deleted: 3, skipped: 0, failed: false })).toBeNull();
+		expect(bulkDeleteFailure({ deleted: 0, skipped: 2, failed: false })).toBeNull();
+	});
+	it('is null when failed but no verbatim error (thrown fetch) - toast falls back', () => {
+		expect(bulkDeleteFailure({ deleted: 0, skipped: 0, failed: true })).toBeNull();
+	});
 });