@@ -363,8 +363,14 @@ export default defineCommand({
     catch {
       // Use default buildDir (.nuxt)
     }
-    await cleanupNuxtDirs(cwd, buildDir, { silent: true })
-    cleanupSpinner.stop('Build directories cleaned')
+    try {
+      await cleanupNuxtDirs(cwd, buildDir, { silent: true })
+      cleanupSpinner.stop('Build directories cleaned')
+    }
+    catch (err) {
+      cleanupSpinner.stop('Could not clean build directories')
+      logger.warn(`Nuxt was upgraded but build directories could not be removed: ${err instanceof Error ? err.message : err}`)
+    }
 
     if (method === 'force') {
       logger.info(`If you encounter any issues, revert the changes and try with ${styleText('cyan', '--no-force')}`)
 
@@ -130,11 +130,24 @@ export async function runDedupe(options: DedupeOptions): Promise<InstallResult>
     return await runInstall(options)
   }
 
-  const { exec } = await dedupeDependencies({
-    cwd: options.cwd,
-    packageManager: options.packageManager,
-    dry: true,
-  })
+  let exec
+  try {
+    ({ exec } = await dedupeDependencies({
+      cwd: options.cwd,
+      packageManager: options.packageManager,
+      recreateLockfile: false,
+      dry: true,
+    }))
+  }
+  catch (error) {
+    return {
+      success: false,
+      output: '',
+      command: '',
+      ignoredBuilds: [],
+      error: error instanceof Error ? error.message : String(error),
+    }
+  }
 
   if (!exec) {
     return { success: true, output: '', command: '', ignoredBuilds: [] }
 
@@ -159,6 +159,16 @@ describe('runDedupe', () => {
     expect(existsSync(localLockFile)).toBe(true)
   })
 
+  it('should report unsupported dedupe commands as failures', async () => {
+    const result = await runDedupe({
+      cwd: process.cwd(),
+      packageManager: { name: 'bun', command: 'bun' },
+    })
+
+    expect(result.success).toBe(false)
+    expect(result.error).toBe('Deduplication is not supported for bun')
+  })
+
   it('should report a missing package manager instead of throwing', async () => {
     const result = await runDedupe({
       cwd: process.cwd(),