pw_env_setup: Log packages before/after deduping

Change-Id: I04a5aae3853dccc41b9d617ba76aac3d099c1e90
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/151654
Presubmit-Verified: CQ Bot Account <pigweed-scoped@luci-project-accounts.iam.gserviceaccount.com>
Commit-Queue: Auto-Submit <auto-submit@pigweed.google.com.iam.gserviceaccount.com>
Pigweed-Auto-Submit: Rob Mohr <mohrr@google.com>
Reviewed-by: Anthony DiGirolamo <tonymd@google.com>
diff --git a/pw_env_setup/py/pw_env_setup/cipd_setup/update.py b/pw_env_setup/py/pw_env_setup/cipd_setup/update.py
index deff9d5..c3c6483 100755
--- a/pw_env_setup/py/pw_env_setup/cipd_setup/update.py
+++ b/pw_env_setup/py/pw_env_setup/cipd_setup/update.py
@@ -215,14 +215,19 @@
         if package['path'] in deduped:
             del deduped[package['path']]
         deduped[package['path']] = package
-    return reversed(list(deduped.values()))
+    return list(reversed(list(deduped.values())))
 
 
 def write_ensure_file(
     package_files, ensure_file, platform
 ):  # pylint: disable=redefined-outer-name
+    logdir = os.path.dirname(ensure_file)
     packages = all_packages(package_files)
+    with open(os.path.join(logdir, 'all-packages.json'), 'w') as outs:
+        json.dump(packages, outs, indent=4)
     deduped_packages = deduplicate_packages(packages)
+    with open(os.path.join(logdir, 'deduped-packages.json'), 'w') as outs:
+        json.dump(deduped_packages, outs, indent=4)
 
     with open(ensure_file, 'w') as outs:
         outs.write(