"Feature flag not set" and "Failed to forward CDN loop header" errors on the edge

We got a ton of these errors in edge function logs. It doesn’t seem related to our code. Is this something we need to worry about? What does it mean practically? Does the request fail or is it forwarded based on redirect rules at that point? Can this be caused by our code?

May 2, 03:00:41 PM: info   StructuredLogger {
May 2, 03:00:41 PM: info     fields: {
May 2, 03:00:41 PM: info       error: "Feature flag not set",
May 2, 03:00:41 PM: info       error_cause: undefined,
May 2, 03:00:41 PM: info       error_stack: "Error: Feature flag not set\n" +
May 2, 03:00:41 PM: info         "    at file:///root/src/bootstrap/util/fetch.ts:86:23\n" +
May 2, 03:00:41 PM: info         "    at f (file:///"... 600 more characters
May 2, 03:00:41 PM: info     },
May 2, 03:00:41 PM: info     logLevel: 2,
May 2, 03:00:41 PM: info     message: "Failed to forward CDN loop header",
May 2, 03:00:41 PM: info     rawLogger: [Function: log],
May 2, 03:00:41 PM: info     requestID: undefined,
May 2, 03:00:41 PM: info     __netlifyStructuredLogger: 1
May 2, 03:00:41 PM: info   }

Nope, nothing to worry about! We’re working on Loop protection for Functions and Edge Functions, and this error message should’ve went to netlify-internal logs. I made a small mistake, so now they’re going to user logs. Working on a fix!

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Alright, fix was rolled out. Please let me know if you’re still seeing those log lines.

BTW, welcome to the Netlify Forums Matyáš! Happy to have you :smiling_face:

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Thx, I’ll keep an eye on it, we had a bunch this night, but then silence, now it seems fine.

Yea, I’ve been using netlify for years, just never had a problem that’d require support here, I guess :man_shrugging: