diff --git a/releng/.gitignore b/releng/.gitignore
new file mode 100644
index 000000000..8d033f940
--- /dev/null
+++ b/releng/.gitignore
@@ -0,0 +1,2 @@
+# Created by `python -m releng tag`
+/prev-git-branch.txt
diff --git a/releng/create_release.xsh b/releng/create_release.xsh
index 0091a6728..41fc84c19 100644
--- a/releng/create_release.xsh
+++ b/releng/create_release.xsh
@@ -32,9 +32,6 @@ RELENG_MSG = "Release created with releng/create_release.xsh"
 BUILD_CORES = 16
 MAX_JOBS = 2
 
-# Workaround for bug in garage: https://git.deuxfleurs.fr/Deuxfleurs/garage/issues/963
-S3_ARGS = ['--checksum-algorithm=SHA256']
-
 
 def setup_creds(env: RelengEnvironment):
     key = keys.get_ephemeral_key(env)
@@ -240,7 +237,20 @@ def upload_artifacts(env: RelengEnvironment, noconfirm=False, no_check_git=False
         docker.upload_docker_images(target, docker_images)
 
     print('[+] Upload to release bucket')
-    aws s3 cp @(S3_ARGS) --recursive @(ARTIFACTS)/ @(env.releases_bucket)/
+
+    # There may or may not be a bug in `garage` here. Previously we added
+    # `--checksum-algorithm=SHA256` here to fix it, but when @9999years was
+    # running the release for 2.93.0, she found it actually made the S3 uploads
+    # fail.
+    #
+    # If this command is failing, here are some links to investigate.
+    #
+    # See: https://git.deuxfleurs.fr/Deuxfleurs/garage/issues/963
+    # See: https://git.deuxfleurs.fr/Deuxfleurs/garage/issues/1017
+    # See: https://github.com/boto/boto3/issues/4392
+    # See: https://docs.aws.amazon.com/cli/v1/userguide/cli-configure-envvars.html#envvars-list-AWS_REQUEST_CHECKSUM_CALCULATION
+    aws s3 cp --recursive @(ARTIFACTS)/ @(env.releases_bucket)/
+
     print('[+] Upload manual')
     upload_manual(env)
 
@@ -287,9 +297,9 @@ def upload_manual(env: RelengEnvironment):
         version = 'nightly'
 
     print('[+] aws s3 sync manual')
-    aws s3 sync @(S3_ARGS) --delete @(MANUAL)/ @(env.docs_bucket)/manual/lix/@(version)/
+    aws s3 sync --delete @(MANUAL)/ @(env.docs_bucket)/manual/lix/@(version)/
     if OFFICIAL_RELEASE:
-        aws s3 sync @(S3_ARGS) --delete @(MANUAL)/ @(env.docs_bucket)/manual/lix/stable/
+        aws s3 sync --delete @(MANUAL)/ @(env.docs_bucket)/manual/lix/stable/
 
 
 def build_artifacts(build_profile, no_check_git=False):
diff --git a/releng/docker_assemble.py b/releng/docker_assemble.py
index d5b47c328..21754336b 100644
--- a/releng/docker_assemble.py
+++ b/releng/docker_assemble.py
@@ -248,7 +248,8 @@ class AuthState:
             with path.open() as fh:
                 try:
                     json_obj = json.load(fh)
-                    return {k: v['auth'] for k, v in json_obj['auths'].items()}
+                    auths = json_obj.get('auths', {})
+                    return {k: v['auth'] for k, v in auths.items()}
                 except (json.JSONDecodeError, KeyError) as e:
                     log.exception('JSON decode error in %s', path, exc_info=e)
         return {}
diff --git a/releng/local/default.nix b/releng/local/default.nix
index 64c617a57..48d710dd2 100644
--- a/releng/local/default.nix
+++ b/releng/local/default.nix
@@ -1,8 +1,6 @@
 {
   self,
   system,
-  lib,
-  config,
   pkgs,
   ...
 }: