I was working on finishing my workflow, when suddenly I started seeing nonsensical errors. It turns out GITHUB_REF and GITHUB_SHA are no longer getting set!
Running cmd /c "set" on Windows gives:
[...] GITHUB_BASE_REF= GITHUB_EVENT_NAME=push GITHUB_EVENT_PATH=d:\a\_temp\_github_workflow\event.json GITHUB_HEAD_REF= GITHUB_REF= GITHUB_REPOSITORY=nulano/Pillow GITHUB_SHA= [...]
This broke about an hour ago.
Also see this issue: https://github.com/actions/checkout/issues/49
Solved! Solved! Go to Solution.