Getting runtime contexts will generate an E_WARNING for anonymous users

assuming bot agrees

Thanks for raising this. The Rules issue which shows examples of the test failures is #2936553: Rules kernel tests fail with "Creating default object from empty value"

I will test this core patch locally but it looks fine at first glance.

I've tested #2 locally on 8.5.x with Rules dev and the failing tests now pass. So I am also happy with the RTBC.

Would be great to get this committed to 8.5 and 8.6.

Yes, this is causing Rules to fail testing at 8.5 and 8.6. To show how this core patch fixes the Rules tests I have created a github branch which has a modfied .travis.yml file to conditionally apply the patch from #2 above when running at 8.5.x or above. I used the following:

  # TEMP apply patch from https://www.drupal.org/project/drupal/issues/2936642
  # for core 8.5 and above.
  - |
    if [[ "${DRUPAL_CORE}" > "8.4.x" ]]; then
      wget https://www.drupal.org/files/issues/2936642-context-2.patch;
      git apply -v -p1 < 2936642-context-2.patch;
    fi

The github branch is https://github.com/jonathan1055/rules/tree/2936642-context-warning
n.b. this branch also has the test fix from #2936679-3: Autocomplete test needs values for "Default Revision" flag

The Travis test job is https://travis-ci.org/jonathan1055/rules/builds/330574666

It's good that this fixes the Rules tests, but is there a reason we cant add core test coverage for this?

I'm sure a test could be added to Core to check the context handler for anon users, but I don't know how to do that. This ia a bug that was introduced in #2671964: ContextHandler cannot validate constraints and is blocking development on Rules because the tests do not pass. If the only reason for not committing this correction is a lack of Core test coverage then can we find someone who does know how to write the test?

Agree, this is a test-only edge case and we're blocking contrib here.

Committed as c3ebbc4 and pushed to 8.6.x. Thanks!

Cherry-picked as dd5bae6 and pushed to 8.5.x

Just for the record, the six failing Rules tests were:

Kernel/Engine/MetadataAssertionTest.php:76  (testAssertingEntityBundle)
Kernel/Engine/MetadataAssertionTest.php:114 (testAssertingWithLogicalOperations)
Kernel/Engine/MetadataAssertionTest.php:153 (testAssertingOfNegatedConditions)
Kernel/Engine/AutocompleteTest.php:64 (testAutocomplete)
Kernel/Engine/AutocompleteTest.php:89 (testNodeAutocomplete)
Kernel/Engine/AutocompleteTest.php:352 (testListAutocomplete)
Kernel/RulesEngineTest.php:107 (testProvidedVariables)

In #12 tim.plunkett said

The only way to run into this problem is by writing a unit test that makes incorrect assumptions about the user system.

As this is now a closed issue discussion can continue on #2936553: Rules kernel tests fail with "Creating default object from empty value"