Now

.github/workflows/ci.yml

@@ -71,13 +71,12 @@ jobs:
         run: mix compile --warnings-as-errors
         if: ${{ matrix.lint }}
 
+      # We always need to run tests because code coverage forces us to skip some
+      # tests, so better to run normal tests on the whole matrix and the coverage
+      # only on the latest version.
       - name: Run tests
-        run: |
-          if [ -z "${{ matrix.coverage }}" ]; then
-            echo "Running tests without coverage."
-            mix test
-          else
-            echo "Running tests with coverage."
-            mix test
-            # mix coveralls.html
-          fi
+        run: mix test
+
+      - name: Run tests with coverage
+        if: ${{ matrix.coverage }}
+        run: mix coveralls.github --exclude fails_on_coverage

test/cluster_test.exs

@@ -10,6 +10,9 @@ if otp_release >= 25 do
     use ExUnit.Case
     import Mox
 
+    # These tests don't work if code coverage is enabled.
+    @moduletag :fails_on_coverage
+
     setup_all do
       Task.start_link(fn ->
         System.cmd("epmd", [])