2 files changed, 7 insertions, 1 deletions
diff --git a/src/ci/github-actions/ci.yml b/src/ci/github-actions/ci.yml
index 8f8b10ab90e..ec65b5f37bd 100644
--- a/src/ci/github-actions/ci.yml
+++ b/src/ci/github-actions/ci.yml
@@ -340,6 +340,7 @@ concurrency:
   cancel-in-progress: true
 
 jobs:
+  # The job matrix for `calculate_matrix` is defined in src/ci/github-actions/jobs.yml.
   calculate_matrix:
     name: Calculate job matrix
     runs-on: ubuntu-latest
@@ -362,6 +363,7 @@ jobs:
     continue-on-error: ${{ matrix.name == 'mingw-check-tidy' }}
     strategy:
       matrix:
+        # Check the `calculate_matrix` job to see how is the matrix defined.
         include: ${{ fromJSON(needs.calculate_matrix.outputs.jobs) }}
 
   auto:
diff --git a/src/ci/github-actions/jobs.yml b/src/ci/github-actions/jobs.yml
index 5b0140053d6..7e89eef2670 100644
--- a/src/ci/github-actions/jobs.yml
+++ b/src/ci/github-actions/jobs.yml
@@ -1,4 +1,8 @@
-x--expand-yaml-anchors--remove:
+# This file contains definitions of CI job parameters that are loaded
+# dynamically in CI from ci.yml.
+# You *do not* need to re-run `src/tools/expand-yaml-anchors` when you
+# modify this file.
+shared_defs:
   - &base-job
     env: { }