Created by: ro-savage
Fixes #2399 (closed)
Yarn is caching old react-scripts when running the e2e tests, which means old versions are being used during the build process. Fine for CI where each build is on a clean machine but breaks e2e in unforeseen ways on local machines.
This might be related to yarnpkg/yarn#2165
The fix is to run yarn clean cache before running the e2e tests.