[Bug]: When using `next export`, cache not found

[Redmega]

Summary

According to the docs, this plugin should be able to handle caching the build folder from a next exported project. However in practice, the plugin seems to be looking at the publish directory for the cache folder, which would not exist when you publish the out/ directory, like in the demo project.

https://github.com/netlify/netlify-plugin-nextjs/blob/b27c2f299c47ff387e726f76ad03847271e9d8e5/src/helpers/cache.ts#L13-L22

In this case you would want to cache the .next/cache folder, because the .next folder is what actually gets built -- the export command pulls the data it needs from the .next folder.

Steps to reproduce

1. Publish the demo export
2. Go to the logs
3. See that it does not cache.

Plugin version

v4.2.3

Your netlify.toml file

`netlify.toml`

[build]
command = "yarn build" # "next build && next export"
publish = "out/"

[build.environment]
NETLIFY_NEXT_PLUGIN_SKIP = "true"

Builds logs (or link to your logs)

Build logs

1:38:19 PM:   2. build.command from netlify.toml                            
1:38:19 PM: ────────────────────────────────────────────────────────────────
[...]
1:38:19 PM: ​
 info  - using build directory: /opt/build/repo/.next
1:39:04 PM: info  - Copying "static build" directory
1:39:04 PM: info  - No "exportPathMap" found in "/opt/build/repo/next.config.js". Generating map from "./pages"
1:39:04 PM: info  - Launching 7 workers
1:39:04 PM: info  - Exporting (0/2)
1:39:04 PM: info  - Copying "public" directory
1:39:05 PM: info  - Exporting (2/2)
1:39:05 PM: Export successful. Files written to /opt/build/repo/out
1:39:05 PM: Done in 46.10s.
[...]

1:39:05 PM: ────────────────────────────────────────────────────────────────
1:39:05 PM:   4. @netlify/plugin-nextjs (onPostBuild event)                 
1:39:05 PM: ────────────────────────────────────────────────────────────────
1:39:05 PM: ​
1:39:05 PM: No Next.js cache to save.
1:39:05 PM: ​
1:39:05 PM: (@netlify/plugin-nextjs onPostBuild completed in 5ms)
1:39:05 PM: ​

[ascorbic]

This fix is in version 4.2.7

[Redmega]

Awesome, thank you! When does the version usually propagate to Netlify plugins in the dashboard? I still see 4.2.6 as the latest.

[ascorbic]

@Redmega It looks like it's there now

[PinkaminaDianePie]

@Redmega this fix doesn't work for v5 - plugin doesn't use cache at all

[Redmega]

Unfortunately I no longer work at the place where this issue was relevant 😅 I'd recommend opening a new bug so you can get help yourself.

[brijeshb42]

This is still an issue and should be re-opened. It occurs when using { output: "export" } in next.js.

The plugin is looking for cache folder in publishDir but publishDir in our case would be out folder which lives at the same level as the .next folder.