Compare build config/cache between two builds

Is there any way to compare the cached build/deploy config between two deployments? And what is cached, is it just the dependencies (ie, the node_modules folder) or more?

Context: We’re hitting a frustrating bug on our site - we have two Netlify ‘sites’ pointing at the same repo, which was initially set up to allow us to have a ‘develop’ branch as the default branch on one site (which can be password protected to hide sensitive WIP), and ‘master’ as the default on another (strictly for production-ready builds and split testing). Since then we’ve moved away from using ‘develop’ as a route to production, but this legacy arrangement persists since we find it useful.

The problem is that, at some point, the build/deploy cache has been cleared on the ‘develop’ site, and on builds on that site we see a strange bug - AFAIK the symptoms of the bug itself are not really relevant to the problem, but I’ve included steps to reproduce at the bottom of this post, in case it’s useful.

What is certain is that two nominally ‘identical’ builds (links below) from the same branch of our repo (master) are displaying different behaviour, and the only reliable difference that I can anticipate is the build/deploy cache on each site.

Furthermore, our repo doesn’t currently have a package-lock.json file, which is another clue that it’s likely a dependency discrepancy…

So fundamentally I think that’s the question - is there any way to retrieve the cached build/deploy data?

Steps To Reproduce Bug:

  1. Browser must be Google Chrome on desktop (issue does not appear on Android GC nor macOS/iOS Safari, but I’m quite sure this isn’t a GC bug per se, rather an issue with one of the package dependencies in GC)
  2. Visit https://master–bleachlondon-develop.netlify.app
  3. click on the account (person) icon at the top right.
  4. Attempt to click on the input field, expected behaviour would be for the input to become active and the cursor to appear, but nothing happens
  5. Visit https://master–bleach-site.netlify.app Follow steps 3 & 4, input should be functional.

hi there,

here is a little more info on what we cache:

i wonder if downloading your deployed sites would give you a clue as to what is being “kept” and creating differences?

Hi Perry - I had already downloaded the deployed sites, but the differences in output are hard to distinguish, partly because Webpack appends chunk IDs to the files (and there are a lot of chunks).

In any case, the link you’ve shared is related to CDN caching, rather than the build dependency caching - how can I see the dependencies that were used for each build?

The problem is that, if at any time I need to clear the build cache on the production site, we are likely to introduce the bug along with the updated dependencies

I have gleaned from elsewhere on these boards that the build and dependencies are located at something like /opt/build/... but is there any way to access that through CLI, shell or somehow?

Hey @ollyskinner,

We can download the build cache and send it over. Could you confirm that it’s supposed to be done for the latest deploys for both of those sites? A specific deploy ID would be helpful.

Hey @hrishikesh thanks for that - yes, it would be the latest deploys for the ‘master’ branch for both sites, I’ll DM you the IDs

Hey @hrishikesh - I sent you the details on Monday in a DM - in case you’re not about, I’m just bumping here if anyone else on your team is able to help - thanks

Raising again, if anyone on the Netlify support side can help, this is becoming a blocker to feature releases. Thanks

Hey there, @ollyskinner :wave:

Apologies for the delay here. Our team has been short staffed this past week, and as a result our responses have taken a bit longer than we would normally like. We appreciate your understanding.

I have spoken with Hrishikesh, and he has responded via the helpdesk to your inquiry. If you have further questions, please follow up there.

Best,
Hillary

Hey there, @ollyskinner :wave:

Apologies for the delay here. Our team has been short staffed this past week, and as a result our responses have taken a bit longer than we would normally like. We appreciate your understanding.

I have spoken with Hrishikesh, and he has responded via the helpdesk to your inquiry. If you have further questions, please follow up there.

Best,
Hillary

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Thank you for getting back to me @hillary , much appreciated

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