Percy snapshot times out when run on CI

Getting the following:

CypressError: cy.request() timed out waiting 30000ms for a response from your server.
--
4583 |  
4584 | The request we sent was:
4585 |  
4586 | Method: POST
4587 | URL: http://localhost:5338/percy/snapshot

This happens consistently on every run. I am using the following:

• Cypress 4.2
• Cypress docker image (chrome 69)
• Running on AWS Codebuild for CI (using the standard image)

I already bumped SHM to 8g so it seems unlikely that this is the problem. I also disabled Chrome web security.

What is surprising, is that Percy successfully starts the build (and stops it when the build manages to get to that point). Just the snapshot call seems to fail

[wwilsman]

Thanks @OzTK!

Just finished looking those logs over and I think I see what might be causing the issue. I’ll answer here for any future visitors with a similar problem.

I wasn’t entirely correct before when I said there might be assets hanging. But it is indeed the asset discovery service that is hanging. The asset discovery service uses Puppeteer and a page pool to discover assets. What seems to be happening is the page pool is not able to open a Puppeteer page and gets stuck repeatedly trying until the timeout. That’s why you see so many newPage logs.

Unfortunately, the pooling library does not log the error when retrying and so I’m still not entirely sure what is going wrong. I did notice that you are using an image with Chrome 69 and setting Puppeteer environment variables to suppress it’s automatic download. I think maybe this version of Chrome is not compatible with the latest version of Puppeteer. Try removing those Puppeteer environment variables so Puppeteer can download a compatible version to see if it starts working. If it does work, you’ll have to increase your Chrome version to a compatible one.

[OzTK]

Confirming that this problem was solved by updating the Cypress docker image we were using. We re-evaluated our requirements and bumped it to Chrome 78, which worked. It is a big inconvenience not to have control over the browser version when updating Percy though. Cypress allows to target specific versions, which is great, it would be a huge improvement if Percy was doing the same. The main problem is that there is no explicit mentioning of which version of Chrome works with which version of Percy. There is also a discrepancy between the version used in percy-cypress and the one used in percy-storybook (those are the 2 we use). I know this constraint comes with Puppeteer, but making it explicit and documented would save a lot of trouble to users of Percy 🙂