diff --git a/pbrx/container_images.py b/pbrx/container_images.py
index cdde477..d5b7273 100755
--- a/pbrx/container_images.py
+++ b/pbrx/container_images.py
@@ -66,6 +66,12 @@ class ContainerContext(object):
                 host=os.path.expanduser('~/.config/pip/pip.conf'),
                 guest='/root/.config/pip/pip.conf'))
         self.create()
+        log.debug(
+            "Used base image {base} at sha {sha}".format(
+                base=self._base,
+                sha=sh.docker.images('-q', self._base).strip(),
+            ))
+
         self._cont = sh.docker.bake("exec", self.run_id, "sh", "-c",
                                     _truncate_exc=False)