Cypress installation error

[ehmicky]

It seems like some builds are having issues running cypress install:

┌───────────────────────────────────────────────────────┐
│ 1. onPreBuild command from netlify-plugin-visual-diff │
└───────────────────────────────────────────────────────┘

no Cypress cache found — installing it now

┌────────────────────────────────────────────────────┐
│ Plugin "netlify-plugin-visual-diff" internal error │
└────────────────────────────────────────────────────┘

Error message
Error: Command failed with ENOENT: cypress install
spawn cypress ENOENT

cypress is present in package.json, then it should be available in node_modules/.bin, so I am not sure what might happen. Something that would debug this problem: if the command throws, print error.stderr and error.stdout (note this requires stdio option to be pipe or not defined).

[jlengstorf]

I followed the lead of netlify-plugin-cypress to store the Cypress binary between builds:
https://github.com/jlengstorf/netlify-plugin-visual-diff/blob/8ca55e2b06c8b35203747d585e080f9c9de37cf8/index.js#L94-L102

I can see that this might be causing issues, though (cypress-io/netlify-plugin-cypress#50)

I have no idea why this wouldn't be available, though. this kind of points back to my suspicion that the cache utils are flaky sometimes (see also https://github.com/netlify/build/issues/1225) — I think they sometimes confirm a save, then miss on restoration

I also have zero idea how a fresh install would be missing. that kind of feels upstream? I'm happy to help debug, but I have no idea where to even start (for example, I don't know what the "stdio option" refers to — which link in this chain needs that option set?)

[ehmicky]

Related too: https://github.com/netlify/build-image-plugins/issues/5

[ehmicky]

It looks like the utils.cache.restore() and utils.cache.save() operations might not be needed here.

When cypress install runs, it is added to ~/.cache/Cypress. ~/.cache is saved and restored to the build cache by default by Netlify buildbot. cypress install detects this automatically and becomes a quick noop instead when Cypress has already been installed/cached.

Actually, if users are already using cypress (including through netlify-plugin-cypress), this will be cached in ~/.cache/Cypress, so having it cached in /opt/buildhome/.cache/Cypress would create duplicate cache (of 580MB).

Also, ../../buildhome/.cache/Cypress would not work when using a base directory, since some additional .. might be needed to reach /opt/buildhome/.

On a different topic: cypress install itself might not be needed. Unless I'm mistaken, this operation is done on postinstall by Cypress. Since cypress is a dependency of netlify-plugin-visual-diff, I think removing that call altogether should work.

I think it might be interesting to see if the plugin still work after removing the two following things?

• utils.cache.restore() and utils.cache.save()
• utils.run('cypress', ['install'])

[jlengstorf]

this was fixed in #2 — please let me know if you see anything in the logs for this one!

[ehmicky]

Thanks @jlengstorf!