CI: Add more logging during docker builds

(cherry picked from commit 3d1380305b)

.cirrus.yml

@@ -437,6 +437,7 @@ docker_build_template: &DOCKER_BUILD_TEMPLATE
     CIRRUS_LOG_TIMESTAMP: true
     BUILDER_IMAGE_CACHE_DIR: /tmp/builder-image-cache
     ZEEK_IMAGE_CACHE_DIR: /tmp/zeek-image-cache-${CIRRUS_ARCH}
+    BUILDKIT_PROGRESS: plain
 
   always:
     ccache_cache:

docker/builder.Dockerfile

@@ -3,6 +3,11 @@
 # Layer to build Zeek.
 FROM debian:bookworm-slim
 
+# Make the shell split commands in the log so we can determine reasons for
+# failures more easily.
+SHELL ["/bin/sh", "-x", "-c"]
+
+# Allow apt to retry 3 times before failing.
 RUN echo 'Acquire::Retries "3";' > /etc/apt/apt.conf.d/80-retries
 
 # Configure system for build.

docker/final.Dockerfile

@@ -3,6 +3,11 @@
 # Final layer containing all artifacts.
 FROM debian:bookworm-slim
 
+# Make the shell split commands in the log so we can determine reasons for
+# failures more easily.
+SHELL ["/bin/sh", "-x", "-c"]
+
+# Allow apt to retry 3 times before failing.
 RUN echo 'Acquire::Retries "3";' > /etc/apt/apt.conf.d/80-retries
 
 RUN apt-get -q update \