diff --git a/docs/downloads/bitbucket-pipelines.yml b/docs/downloads/bitbucket-pipelines.yml
index 0c3c256e7..ff3295905 100644
--- a/docs/downloads/bitbucket-pipelines.yml
+++ b/docs/downloads/bitbucket-pipelines.yml
@@ -40,7 +40,13 @@ pipelines:
           script:
             - git clone --shallow-since="6 months ago" --no-tags https://x-token-auth:$oauth_token@bitbucket.org/$full_repo.git gitstream/repo
             - git clone --depth=1 --no-tags https://x-token-auth:$oauth_token@bitbucket.org/$BITBUCKET_WORKSPACE/$BITBUCKET_REPO_SLUG.git gitstream/cm
-            - cd gitstream/repo && git fetch origin $head_ref:$head_ref && git checkout $head_ref
+            - |
+              set -e
+              cd gitstream/repo
+              git checkout --detach
+              # Fetch all branches so any base branch can be diffed; keep --shallow-since or this pulls full history.
+              git fetch --no-tags --force --shallow-since="6 months ago" origin '+refs/heads/*:refs/heads/*'
+              git checkout "$head_ref"
             - docker pull gitstream/rules-engine:latest
             - |
               docker run -v $BITBUCKET_CLONE_DIR/gitstream:/code \
diff --git a/docs/downloads/gitlab-ci.yml b/docs/downloads/gitlab-ci.yml
index f4a952d0b..7169b7894 100644
--- a/docs/downloads/gitlab-ci.yml
+++ b/docs/downloads/gitlab-ci.yml
@@ -27,7 +27,13 @@ gitstream-job:
   script:
     - git clone --shallow-since="6 months ago" --no-tags https://gitlab-ci-token:${CI_JOB_TOKEN}${repoUrl} gitstream/repo
     - git clone --depth=1 --no-tags https://gitlab-ci-token:${CI_JOB_TOKEN}${cmUrl} gitstream/cm
-    - cd gitstream/repo && git fetch origin $head_ref:$head_ref && git checkout $head_ref
+    - |
+      set -e
+      cd gitstream/repo
+      git checkout --detach
+      # Fetch all branches so any base branch can be diffed; keep --shallow-since or this pulls full history.
+      git fetch --no-tags --force --shallow-since="6 months ago" origin '+refs/heads/*:refs/heads/*'
+      git checkout "$head_ref"
     - docker pull gitstream/rules-engine:latest
     - |
       docker run -v $CI_PROJECT_DIR/gitstream:/code \
diff --git a/docs/downloads/gitlab-k8s-ci.yml b/docs/downloads/gitlab-k8s-ci.yml
index c202a9c15..3feab3e58 100644
--- a/docs/downloads/gitlab-k8s-ci.yml
+++ b/docs/downloads/gitlab-k8s-ci.yml
@@ -26,7 +26,13 @@ gitstream-job:
   script:
     - git clone --shallow-since="6 months ago" --no-tags https://gitlab-ci-token:${CI_JOB_TOKEN}${repoUrl} gitstream/repo
     - git clone --depth=1 --no-tags https://gitlab-ci-token:${CI_JOB_TOKEN}${cmUrl} gitstream/cm
-    - cd gitstream/repo && git fetch origin $head_ref:$head_ref && git checkout $head_ref
+    - |
+      set -e
+      cd gitstream/repo
+      git checkout --detach
+      # Fetch all branches so any base branch can be diffed; keep --shallow-since or this pulls full history.
+      git fetch --no-tags --force --shallow-since="6 months ago" origin '+refs/heads/*:refs/heads/*'
+      git checkout "$head_ref"
     - docker pull gitstream/rules-engine:latest
     - |
       docker run -v $CI_PROJECT_DIR/gitstream:/code \
diff --git a/docs/downloads/gitlab-shell-ci.yml b/docs/downloads/gitlab-shell-ci.yml
index 0f8eb279e..7827514a2 100644
--- a/docs/downloads/gitlab-shell-ci.yml
+++ b/docs/downloads/gitlab-shell-ci.yml
@@ -20,7 +20,13 @@ gitstream-job:
   script:
     - git clone --shallow-since="6 months ago" --no-tags https://gitlab-ci-token:${CI_JOB_TOKEN}${repoUrl} gitstream/repo
     - git clone --depth=1 --no-tags https://gitlab-ci-token:${CI_JOB_TOKEN}${cmUrl} gitstream/cm
-    - cd gitstream/repo && git fetch origin $head_ref:$head_ref && git checkout $head_ref
+    - |
+      set -e
+      cd gitstream/repo
+      git checkout --detach
+      # Fetch all branches so any base branch can be diffed; keep --shallow-since or this pulls full history.
+      git fetch --no-tags --force --shallow-since="6 months ago" origin '+refs/heads/*:refs/heads/*'
+      git checkout "$head_ref"
     - docker pull gitstream/rules-engine:latest
     - |
       docker run -v $CI_PROJECT_DIR/gitstream:/code \