diff --git a/packages/edge-bundler/deno/vendor/deno.land/x/eszip@v0.55.2/eszip.ts b/packages/edge-bundler/deno/vendor/deno.land/x/eszip@v0.55.2/eszip.ts
index 3ed2bb0286..23a1935fcb 100644
--- a/packages/edge-bundler/deno/vendor/deno.land/x/eszip@v0.55.2/eszip.ts
+++ b/packages/edge-bundler/deno/vendor/deno.land/x/eszip@v0.55.2/eszip.ts
@@ -81,6 +81,7 @@ class V2 {
     const imports: Record<string, string> = {};
 
     for (const specifier of this.specifiers) {
+      if (new URL(specifier).protocol !== "file:") continue
       const module = await this.parser.getModuleSource(specifier);
       await write(join(dest, "source", url2path(specifier)), module);
       // Track import
@@ -107,11 +108,8 @@ export async function loadESZIP(filename: string): Promise<ESZIP> {
   return await V1.load(bytes);
 }
 
-function url2path(urlString: string) {
-  const url = new URL(urlString);
-  const tail = url.pathname.split("/").filter(Boolean);
-  const relativePath = tail.length === 0 ? [".root"] : tail;
-  return join(url.hostname, ...relativePath);
+function url2path(url: string) {
+  return join(...(new URL(url).pathname.split("/").filter(Boolean)));
 }
 
 async function write(path: string, content: string) {
diff --git a/packages/edge-bundler/node/bundler.ts b/packages/edge-bundler/node/bundler.ts
index d9fbf5eea3..52ce09334a 100644
--- a/packages/edge-bundler/node/bundler.ts
+++ b/packages/edge-bundler/node/bundler.ts
@@ -22,6 +22,7 @@ import { writeManifest } from './manifest.js'
 import { vendorNPMSpecifiers } from './npm_dependencies.js'
 import { ensureLatestTypes } from './types.js'
 import { nonNullable } from './utils/non_nullable.js'
+import { BundleError } from './bundle_error.js'
 
 export interface BundleOptions {
   basePath?: string
@@ -249,26 +250,35 @@ const getFunctionConfigs = async ({
       throw err
     }
 
-    // We failed to extract the configuration because there is an import assert
-    // in the function code, a deprecated feature that we used to support with
-    // Deno 1.x. To avoid a breaking change, we treat this error as a special
-    // case, using the generated ESZIP to extract the configuration. This works
-    // because import asserts are transpiled to import attributes.
-    const extractedESZIP = await extractESZIP(deno, eszipPath)
-    const configs = await Promise.all(
-      [...internalFunctions, ...userFunctions].map(async (func) => {
-        const relativePath = relative(basePath, func.path)
-        const functionPath = join(extractedESZIP.path, relativePath)
-
-        return [func.name, await getFunctionConfig({ functionPath, importMap, deno, log })] as const
-      }),
-    )
+    try {
+      // We failed to extract the configuration because there is an import assert
+      // in the function code, a deprecated feature that we used to support with
+      // Deno 1.x. To avoid a breaking change, we treat this error as a special
+      // case, using the generated ESZIP to extract the configuration. This works
+      // because import asserts are transpiled to import attributes.
+      const extractedESZIP = await extractESZIP(deno, eszipPath)
+      const configs = await Promise.all(
+        [...internalFunctions, ...userFunctions].map(async (func) => {
+          const relativePath = relative(basePath, func.path)
+          const functionPath = join(extractedESZIP.path, relativePath)
 
-    await extractedESZIP.cleanup()
+          return [func.name, await getFunctionConfig({ functionPath, importMap, deno, log })] as const
+        }),
+      )
 
-    return {
-      internalFunctions: Object.fromEntries(configs.slice(0, internalFunctions.length)),
-      userFunctions: Object.fromEntries(configs.slice(internalFunctions.length)),
+      await extractedESZIP.cleanup()
+
+      return {
+        internalFunctions: Object.fromEntries(configs.slice(0, internalFunctions.length)),
+        userFunctions: Object.fromEntries(configs.slice(internalFunctions.length)),
+      }
+    } catch (err) {
+      throw new BundleError(
+        new Error(
+          'An error occurred while building an edge function that uses an import assertion. Refer to https://ntl.fyi/import-assert for more information.',
+        ),
+        { cause: err },
+      )
     }
   }
 }