I have opened a PR from my fork of a repository to the upstream repository. Both repositories can run Github Actions. But the PR itself does not show any information on the checks.
This is the PR:
As you see the checks are empty. But on the forked repository I see the actions being executed: https://github.com/phw/picard/commit/59b88f41e6e9502c08d033c1a9b4e82de6ec36be/checks?check_suite_id=333414038
As I understood Actions so far, the actions should be executed on the fork for security reason, but they should still show up in the PR. This is how other CI systems, e.g. Travis or Appveyor, also behave.