diff --git a/src/components/Sidebar.astro b/src/components/Sidebar.astro
index c9ac403..830150c 100644
--- a/src/components/Sidebar.astro
+++ b/src/components/Sidebar.astro
@@ -2,17 +2,7 @@
 import type { PageEntry } from "../layouts/PagesLayout.astro";
 
 const entry: PageEntry = Astro.props.entry;
-const basePath: string = Astro.props.basePath;
-
-const entryPath = is_index_file(entry.path)? "": entry.path;
-
-const entryUrl = basePath + entryPath + (entryPath.endsWith("/")? "" : "/");
-
-function is_index_file(p) {
-	return p.endsWith("index")
-		|| p.endsWith("index.md")
-		|| p.endsWith("index.mdx")
-}
+const post_url = entry.url + (entry.url.endsWith("/") ? "" : "/");
 ---
 
 {
@@ -20,7 +10,7 @@ function is_index_file(p) {
         <li>
             <a
                 class="inline-block rounded-2xl w-full hover:bg-neutral-200 dark:hover:bg-neutral-800 transition-colors px-3 py-2"
-                href={entryUrl}
+                href={post_url}
             >
                 {entry.title}
             </a>
@@ -38,7 +28,6 @@ function is_index_file(p) {
                 {entry.children!.map((nextEntry) => (
                     <Astro.self
                         entry={nextEntry}
-                        basePath={`${basePath}${entry.path}`}
                     />
                 ))}
             </ul>
diff --git a/src/layouts/NewDocsLayout.astro b/src/layouts/NewDocsLayout.astro
index c3cc8ff..07e7193 100644
--- a/src/layouts/NewDocsLayout.astro
+++ b/src/layouts/NewDocsLayout.astro
@@ -25,29 +25,33 @@ export interface Frontmatter {
 }
 
 type Props = {
-    /** The directory where all the md/mdx files start from */
-    base_dir: string
+    /** Base url. It is used to later build a tree file system */
+    base_url: string,
     frontmatter: Frontmatter;
     headings: any;
     posts: Array<AstroFile>;
 };
 
 const {
-	base_dir,
+	base_url,
 	frontmatter,
 	headings,
 	posts
 }: Props = Astro.props;
 
-const base_dir_end = base_dir.length;
+const base_len = base_url.length;
 
 const posts_2 = posts
-	.map(post => ({
+	.map(post => {
+	return {
 		...post,
-		relative_file: post.file.substring(base_dir_end),
-		path: post.file.substring(base_dir_end).replace(/\.mdx?$/, ""),
 		title: post.frontmatter.title,
-	}))
+		// this should be a path relative to the base url.
+		// e.g if base_url is `/spec`, then this instead of
+		// being `/spec/ast/tokens` would be `/ast/tokens`
+		path: post.url.substring(base_len),
+	}
+	})
 	.sort((p1, p2) => p1.frontmatter.order > p2.frontmatter.order? 1 : -1);
 
 // build a hierarchy of the files
@@ -65,7 +69,7 @@ for (const post of posts_2) {
 		}
 		second_level[folder_name].push(post);
 	}
-	else if (fragments.length === 2) {
+	else {
 		// add to root folder
 		second_level["_"]!.push(post);
 	}
@@ -86,17 +90,24 @@ for (const levels_key in second_level) {
 			path: "",
 			title: levels_key,
 			children: posts,
+			url: "",
 		};
 		entries.push(parentEntry);
 	}
 }
 
-const index_page = entries.find(post => post.relative_file === "/index.md" || post.relative_file === "/index.mdx");
-if (index_page === undefined && process.env.NODE_ENV !== "production") {
+/*
+const index_page = posts_2.find(post => post.relative_file === "/index.md" || post.relative_file === "/index.mdx");
+if (index_page === undefined) {
 	console.error("\n\nBuilding without an index page");
-	console.error("Props base_dir:", base_dir);
+	console.error(import.meta.dirname);
+	console.error("base_path", base_dir);
+	console.error("entries len", entries.length);
+	entries.forEach(e => console.log("\t"+e.url));
+	throw new Error("No entries");
 }
 const basePath = index_page?.url ?? "/";
+*/
 ---
 
 <BaseLayout title={frontmatter.title}>
@@ -113,7 +124,7 @@ const basePath = index_page?.url ?? "/";
             <nav class="py-4 pr-2 overflow-x-scroll h-[calc(100vh-3rem)]">
                 {
                     entries.map((entry) => (
-                        <Sidebar entry={entry} basePath={basePath} />
+                        <Sidebar entry={entry} />
                     ))
                 }
             </nav>
diff --git a/src/pages/en/latest/learn/_wrapper.astro b/src/pages/en/latest/learn/_wrapper.astro
index 79329dd..ad4c022 100644
--- a/src/pages/en/latest/learn/_wrapper.astro
+++ b/src/pages/en/latest/learn/_wrapper.astro
@@ -6,12 +6,12 @@ const { frontmatter, headings } = Astro.props;
 
 const posts = await Astro.glob("./**/*.{md,mdx}") as unknown as Array<AstroFile>;
 
-// Current dir
-const current_dir = import.meta.dirname;
+// The base of every URL under this glob
+const base_url = "/en/latest/learn"
 ---
 
 <NewDocsLayout
-    base_dir={current_dir}
+    base_url={base_url}
     frontmatter={frontmatter}
     headings={headings}
     posts={posts}
diff --git a/src/pages/spec/_wrapper.astro b/src/pages/spec/_wrapper.astro
index fcbf1dc..8138e65 100644
--- a/src/pages/spec/_wrapper.astro
+++ b/src/pages/spec/_wrapper.astro
@@ -6,12 +6,12 @@ const { frontmatter, headings } = Astro.props;
 
 const posts = await Astro.glob("./**/*.{md,mdx}") as unknown as Array<AstroFile>;
 
-// Current dir
-const current_dir = import.meta.dirname;
+// The base of every URL under this glob
+const base_url = "/spec"
 ---
 
 <NewDocsLayout
-    base_dir={current_dir}
+    base_url={base_url}
     frontmatter={frontmatter}
     headings={headings}
     posts={posts}