fix(tasks): route to checked-out task button

apps/emdash-desktop/src/main/core/workspaces/workspace-bootstrap-service.ts

@@ -1,5 +1,5 @@
 import path from 'node:path';
-import { eq, sql } from 'drizzle-orm';
+import { and, eq, isNull, ne, sql } from 'drizzle-orm';
 import { projectManager } from '@main/core/projects/project-manager';
 import type { ProjectProvider, TaskProvider } from '@main/core/projects/project-provider';
 import { sshConnectionManager } from '@main/core/ssh/lifecycle/production-ssh-connection-manager';
@@ -233,13 +233,24 @@ export class WorkspaceBootstrapService {
 
     const resolvedPath = setupResult.data.path;
     if (resolvedPath) {
-      await this.persistPath(
+      const persistedWorkspaceId = await this.persistPath(
         workspaceRow.id,
         resolvedPath,
         workspaceRow.type,
         connectionId,
         intentBranchName
       );
+      if (persistedWorkspaceId !== workspaceRow.id) {
+        const owningTask = await this.findOwningTask(persistedWorkspaceId, task.projectId, task.id);
+        if (owningTask) {
+          return err({
+            type: 'workspace-already-checked-out',
+            branchName: intentBranchName,
+            taskId: owningTask.id,
+            taskName: owningTask.name,
+          });
+        }
+      }
     }
 
     if (connectionId) {
@@ -281,6 +292,27 @@ export class WorkspaceBootstrapService {
     return this.ensureWorkspaceSetup(wsRow, row, task, project);
   }
 
+  private async findOwningTask(
+    workspaceId: string,
+    projectId: string,
+    ignoredTaskId: string
+  ): Promise<{ id: string; name: string } | null> {
+    const rows = await this.db
+      .select({ id: tasks.id, name: tasks.name })
+      .from(tasks)
+      .where(
+        and(
+          eq(tasks.workspaceId, workspaceId),
+          eq(tasks.projectId, projectId),
+          isNull(tasks.archivedAt),
+          ne(tasks.id, ignoredTaskId)
+        )
+      )
+      .limit(1);
+
+    return rows[0] ?? null;
+  }
+
   /**
    * Persists a resolved path (and its derived key) onto a workspace row.
    *

apps/emdash-desktop/src/renderer/features/tasks/main-panel.tsx

@@ -1,4 +1,4 @@
-import { Loader2 } from 'lucide-react';
+import { ExternalLink, Loader2 } from 'lucide-react';
 import { observer } from 'mobx-react-lite';
 import { useEffect } from 'react';
 import { usePanelRef } from 'react-resizable-panels';
@@ -11,7 +11,9 @@ import {
   useTaskViewContext,
   useWorkspaceViewModel,
 } from '@renderer/features/tasks/task-view-context';
+import { useNavigate } from '@renderer/lib/layout/navigation-provider';
 import { panelDragStore } from '@renderer/lib/layout/panel-drag-store';
+import { Button } from '@renderer/lib/ui/button';
 import { ResizablePanel, ResizablePanelGroup } from '@renderer/lib/ui/resizable';
 import { DraggableResizeHandle, TaskMainColumn } from './view/task-main-column';
 import { TaskSidebar } from './view/task-sidebar';
@@ -20,6 +22,7 @@ export const TaskMainPanel = observer(function TaskMainPanel() {
   const { projectId, taskId } = useTaskViewContext();
   const taskStore = getTaskStore(projectId, taskId);
   const kind = taskViewKind(taskStore, projectId);
+  const { navigate } = useNavigate();
 
   if (kind === 'creating') {
     return (
@@ -54,13 +57,29 @@ export const TaskMainPanel = observer(function TaskMainPanel() {
   }
 
   if (kind === 'provision-error' || kind === 'project-error') {
+    const existingTask =
+      taskStore?.provisionError?.type === 'workspace-already-checked-out'
+        ? taskStore.provisionError
+        : null;
+
     return (
       <div className="flex h-full w-full flex-col items-center justify-center p-8">
         <div className="flex max-w-xs flex-col items-center gap-2 text-center">
           <p className="font-mono text-sm font-medium text-foreground-destructive">
             Failed to set up workspace
           </p>
           <p className="font-mono text-xs text-foreground-muted">{taskErrorMessage(taskStore)}</p>
+          {existingTask && (
+            <Button
+              variant="outline"
+              size="sm"
+              className="mt-2 gap-1.5"
+              onClick={() => navigate('task', { projectId, taskId: existingTask.taskId })}
+            >
+              <ExternalLink className="size-3.5" />
+              Open existing task
+            </Button>
+          )}
         </div>
       </div>
     );

apps/emdash-desktop/src/renderer/features/tasks/stores/task-manager.ts

@@ -87,6 +87,10 @@ function formatProvisionWorkspaceError(error: ProvisionWorkspaceError): string {
       return 'Workspace has no intent and no resolved path — cannot provision.';
     case 'setup-failed':
       return `Setup step '${error.stepKind}' failed (${error.stepErrorType})${error.message ? `: ${error.message}` : ''}.`;
+    case 'workspace-already-checked-out':
+      return error.branchName
+        ? `Branch "${error.branchName}" is already checked out by task "${error.taskName}".`
+        : `This workspace is already checked out by task "${error.taskName}".`;
   }
 }
 
@@ -451,6 +455,7 @@ export class TaskManagerStore {
         if (current && isUnprovisioned(current)) {
           current.phase = 'provision-error';
           current.errorMessage = message;
+          current.provisionError = result.error;
         }
       });
       return;

apps/emdash-desktop/src/renderer/features/tasks/stores/task-store.ts

@@ -5,6 +5,7 @@ import { rpc } from '@renderer/lib/ipc';
 import { log } from '@renderer/utils/logger';
 import type { LinkedIssue } from '@shared/core/linked-issue';
 import type {
+  ProvisionWorkspaceError,
   RenameTaskError,
   RenameTaskSuccess,
   Task,
@@ -41,6 +42,7 @@ export class TaskStore {
   data: UnregisteredTaskData | Task;
   phase: UnregisteredTaskPhase | UnprovisionedTaskPhase | null;
   errorMessage: string | undefined = undefined;
+  provisionError: ProvisionWorkspaceError | undefined = undefined;
   provisionProgressMessage: string | null = null;
 
   /** The workspace ID for this task session — null when unprovisioned. */
@@ -119,6 +121,7 @@ export class TaskStore {
     this.state = 'provisioned';
     this.phase = null;
     this.errorMessage = undefined;
+    this.provisionError = undefined;
     this.provisionProgressMessage = null;
     this.viewModel?.initialize();
   }
@@ -133,6 +136,7 @@ export class TaskStore {
     this.state = 'unprovisioned';
     this.phase = phase;
     this.errorMessage = undefined;
+    this.provisionError = undefined;
     this.provisionProgressMessage = null;
 
     // Create stable stores on first registration (when transitioning from unregistered).
@@ -145,6 +149,7 @@ export class TaskStore {
     this.state = 'unprovisioned';
     this.phase = phase;
     this.errorMessage = undefined;
+    this.provisionError = undefined;
     this.provisionProgressMessage = null;
   }
 

apps/emdash-desktop/src/shared/core/tasks/tasks.ts

@@ -131,7 +131,13 @@ export type ProvisionTaskResult = {
 
 export type ProvisionWorkspaceError =
   | { type: 'no-intent' }
-  | { type: 'setup-failed'; stepKind: string; stepErrorType: string; message?: string };
+  | { type: 'setup-failed'; stepKind: string; stepErrorType: string; message?: string }
+  | {
+      type: 'workspace-already-checked-out';
+      branchName?: string;
+      taskId: string;
+      taskName: string;
+    };
 
 export type DeleteTaskOptions = {
   deleteWorktree?: boolean;