By pass "Can't build edge function X: Exceeds maximum edge function size: 4.45 MB / 4 MB"

[SamyPesse]

We have deployments failing since we updated a library (GitbookIO/gitbook#2338). This library is lazy loaded so in theory it should not impact the worker initial load size.

Error: Can't build edge function /(space)/(content)/[[...pathname]]/page: Exceeds maximum edge function size: 4.45 MB / 4 MB

Is there a way to bypass this limit? why is it 4 MB when Cloudflare indicates a limit of 10 MB (https://developers.cloudflare.com/workers/platform/limits/)?

[james-elicx]

Unfortunately this error actually comes from the Vercel CLI and we are unable to do anything about it...

https://github.com/vercel/vercel/blob/9290c57b83cc45a428e4ce96dd4402f97ec7f821/packages/next/src/edge-function-source/get-edge-function-source.ts#L86

You may need to patch the vercel dependency to disable it from throwing an error.

That does sound quite large though... Are you sure that such a big jump is right? It would have to be at least 0.45MB larger than it was before, as that's how far over the limit it is. I would not expect updating a dependency to push you that far over the limit if it was building fine before...

[simplenotezy]

@james-elicx some time have passed; did you manage to resolve it? Or do we need to manually patch the vercel dependency?

[SamyPesse]

@simplenotezy We patched vercel: https://github.com/GitbookIO/gitbook/blob/main/patches/%40vercel%252Fnext%404.3.6.patch
with https://github.com/GitbookIO/gitbook/blob/main/package.json#L31-L33

We use bun, but I think it's possible to do the same with pnpm or npm.

This patch is also for a specific version of it; it has to be updated when we update next/vercel, but it's easy to do as it's a one-line patch.

[james-elicx]

@simplenotezy you would need to patch it, unfortunately we can't do anything about this in next-on-pages since it's part of Vercel's CLI.

[simplenotezy]

Thanks for prompt reply guys. I've managed to patch with patch-package:

diff --git a/node_modules/@vercel/next/dist/index.js b/node_modules/@vercel/next/dist/index.js
index 5cb46cb..5241331 100644
--- a/node_modules/@vercel/next/dist/index.js
+++ b/node_modules/@vercel/next/dist/index.js
@@ -11811,7 +11811,7 @@ var import_path = require("path");
 // src/constants.ts
 var KIB = 1024;
 var MIB = 1024 * KIB;
-var EDGE_FUNCTION_SIZE_LIMIT = 4 * MIB;
+var EDGE_FUNCTION_SIZE_LIMIT = 10 * MIB;
 var DEFAULT_MAX_UNCOMPRESSED_LAMBDA_SIZE = 250 * MIB;
 var LAMBDA_RESERVED_UNCOMPRESSED_SIZE = 25 * MIB;

@james-elicx not sure, but are you also working on the OpenNext project? Wonder if it will be an issue here

[james-elicx]

not sure, but are you also working on the OpenNext project? Wonder if it will be an issue here

Planning to. It won't be an issue there @simplenotezy - the OpenNext adaptor uses the Next.js build output and does not use the Vercel CLI.