-# What we use to tag the Docker image. For development and release
-# candidate packages, the OS package has a "~dev" or "~rc" suffix, but
-# Python requires a ".dev" or "rc" suffix. Arvados-cwl-runner will be
-# expecting the Python-compatible version string when it tries to pull
-# the Docker image, but --build-arg is expecting the OS package
+echo cwl_runner_version $cwl_runner_version python_sdk_version $python_sdk_version
+
+# For development and release candidate packages, the OS package has a "~dev"
+# or "~rc" suffix, but Python requires a ".dev" or "rc" suffix.
+#
+# Arvados-cwl-runner will be expecting the Python-compatible version string
+# when it tries to pull the Docker image, so we use that to tag the Docker
+# image.
+#
+# The --build-arg docker invocation arguments are expecting the OS package