Cache Components, duplicate route names in build output

[yusifaliyevpro]

Hi. I want to ask whether this is a bug. Why does the output show duplicate routes like this? It only happens for dynamic routes.

├ ◐ /[username]/posts
│ └ /[username]/posts

Route (app)
┌ ◐ /
├ ○ /_not-found
├ ◐ /[username]
│ └ /[username]
├ ◐ /[username]/posts
│ └ /[username]/posts
├ ƒ /api/auth/[...all]
├ ◐ /collab
├ ◐ /complete-profile
├ ○ /forgot-password
├ ◐ /forgot-password/[token]
│ └ /forgot-password/[token]
├ ◐ /invite/[token]
│ └ /invite/[token]
├ ○ /login
├ ○ /manifest.webmanifest
├ ◐ /network
├ ○ /opengraph-image.png
├ ◐ /post/[id]
│ └ /post/[id]
├ ◐ /profile
├ ◐ /profile/saved
├ ○ /robots.txt
├ ◐ /rooms
├ ◐ /rooms/[id]
│ └ /rooms/[id]
├ ◐ /settings
├ ◐ /settings/[section]
│ └ /settings/[section]
├ ○ /signup
├ ƒ /sitemap.xml
└ ◐ /verify-email/[token]
  └ /verify-email/[token]

ƒ Proxy (Middleware)

○  (Static)             prerendered as static content
◐  (Partial Prerender)  prerendered as static HTML with dynamic server-streamed content
ƒ  (Dynamic)            server-rendered on demand

[icyJoseph]

Mmm likely some filtering is missing on the printing step. x-ref: #89344

[icyJoseph]

Ok, so this is intentional, even found a test for it, but my justification is as follows:

The top level (├ ◐ /[username]/posts): This is the route definition - the file that exists in your app directory.

Nested items (│ └ /[username]/posts): These show what was actually prerendered as static shells. In this case, a fallback static shell was generated for the dynamic pattern itself.

This is more noticeable and helpful for permutations on routes with multiple dynamic segments. For example /[category]/[slug] in something like:

  export function generateStaticParams() {                                                                                                                               
    return [                                                                                                                                                             
      { category: 'tech' },                    // partial - only category                                                                                                
      { category: 'tech', slug: 'intro' },     // complete                                                                                                               
      { category: 'sports', slug: 'news' },    // complete                                                                                                               
    ]                                                                                                                                                                    
  } 

Then I'd guess you see:

  └ ◐ /[category]/[slug]                                                                                                                                                 
    ├ /[category]/[slug]    ← fallback shell (both params dynamic)                                                                                                       
    ├ /tech/[slug]          ← partial shell (category resolved, slug dynamic)                                                                                            
    ├ /tech/intro           ← fully prerendered                                                                                                                          
    └ /sports/news          ← fully prerendered   

tech/[slug] is not repeated, right, but a partial shell so-to-speak, in the same category as [category]/[slug]

[Dagris]

Hi @yusifaliyevpro!

This is not a bug, but rather the expected build output format when using Partial Prerendering (PPR) .

The duplicate looking lines represent the two different phases of the route rendering:

1. The Parent Line : Represents the Static Shell of the page. This is the initial HTML that gets served immediately from the cache/CDN.
2. The Indented Line : Represents the Dynamic Holes (usually components wrapped in <Suspense>) that are streamed in dynamically after the shell loads.

The legend at the bottom confirms this with the ◐ symbol:

(Partial Prerender) prerendered as static HTML with dynamic server-streamed content

[yusifaliyevpro]

Thanks for the answer. Adding extra indicators in the build output, such as ○, ◐, or ƒ, would help. Otherwise, people may wonder why this happened and end up searching the Next.js docs or discussions.