We have recently had an issue where a new feature was deployed but did not work on the live UAT environment despite being fine in local dev.
By running client console commands we were able to see that a recently upgraded package was running as the old version in UAT but not locally. This was the root cause of the bug.
Our app's pipeline uses the generic 'node' cache. Deleting this cache manually from the Pipelines UI led to the build completing correctly (same client console command now indicates the correct package version is deployed to production).
If this is all as it seems to be then this seems to be a very dangerous situation. In this case it was obvious there was a problem but more subtle bugs may not be detected so easily in UAT.
If it is indeed best practise to clear caches manually when dependencies change then it seems to me that a logical extension to this would be to link a cache to one or more files (i.e. node cache would be linked to `package-lock.json`) and if the linked file changes have the Pipeline clear the cache at the start.
I feel though that I must have missed something here as I would expect the above to cause plenty of problems for people if it is the expected behaviour.
