Upgrading our Xcode image from 9.4.1 to 10.1.0 seemed to cause some caching issues with yarn.
Specificlally, we were saving our yarn cache to and restoring from:
However after upgrading to 10.1.0, restoring the cache from that directory seemed to be failing (or rather a 32B cache was being restored successfully, though obviously incorrectly).
This commit seems to suggest that macOS is opinionated on the default cache location, and yarn switched to match that. However this commit has been in yarn since ~0.16 roughly, so very early on.
I’m not 100% sure why the image change would cause the problem. Changing the cache restore location to
resolves the problem, I’m just interested to know why it happened